Proposed fix for issue #182 Thread safety

[f20]

This pull request provides a test for multi-threaded workbook creation, code modifications to enable the test to pass, updated POD documentation, and an example script demonstrating multi-threaded workbook creation.

[shawnlaffan]

This PR might still need some work as File::Path::rmdir does not work well under threads on recent Windows perls.

On Strawberry Perl 5.38.2.2 I get the warnings below, and the temp dirs are not cleaned up.

A fallback to File::Path::Tiny might work. I know it has been discussed in #182 but local testing shows it cleans up the temp dirs when run under threads.

See also discussion under StrawberryPerl/Perl-Dist-Strawberry#146

prove -b t\regression\multithreaded01.t
t\regression\multithreaded01.t .. cannot remove directory for C:/Users/user/AppData/Local/Temp/1RQIu8NVJb: Directory not empty at C:/perls/5.38.2.2_PDL/perl/lib/File/Temp.pm line 2643 thread 6.
cannot remove directory for C:/Users/user/AppData/Local/Temp/l6CVhPK03r: Directory not empty at C:/perls/5.38.2.2_PDL/perl/lib/File/Temp.pm line 2643 thread 6.
cannot remove directory for C:/Users/user/AppData/Local/Temp/dBdC1ivKbm: Directory not empty at C:/perls/5.38.2.2_PDL/perl/lib/File/Temp.pm line 2643 thread 6.
cannot remove directory for C:/Users/user/AppData/Local/Temp/QNb4K5D6_0: Directory not empty at C:/perls/5.38.2.2_PDL/perl/lib/File/Temp.pm line 2643 thread 6.
cannot remove directory for C:/Users/user/AppData/Local/Temp/NAjHivjNbc: Directory not empty at C:/perls/5.38.2.2_PDL/perl/lib/File/Temp.pm line 2643 thread 6.
cannot remove directory for C:/Users/user/AppData/Local/Temp/nj6SpjY1gw: Directory not empty at C:/perls/5.38.2.2_PDL/perl/lib/File/Temp.pm line 2643 thread 6.
cannot remove directory for C:/Users/user/AppData/Local/Temp/APXPvXE6MW: Directory not empty at C:/perls/5.38.2.2_PDL/perl/lib/File/Temp.pm line 2643 thread 6.
cannot remove directory for C:/Users/user/AppData/Local/Temp/_Qdc80JNQu: Directory not empty at C:/perls/5.38.2.2_PDL/perl/lib/File/Temp.pm line 2643 thread 2.
cannot remove directory for C:/Users/user/AppData/Local/Temp/oWM8vXJXP0: Directory not empty at C:/perls/5.38.2.2_PDL/perl/lib/File/Temp.pm line 2643 thread 2.
cannot remove directory for C:/Users/user/AppData/Local/Temp/LdeWEEQqB1: Directory not empty at C:/perls/5.38.2.2_PDL/perl/lib/File/Temp.pm line 2643 thread 2.
cannot remove directory for C:/Users/user/AppData/Local/Temp/8y9naxYdrU: Directory not empty at C:/perls/5.38.2.2_PDL/perl/lib/File/Temp.pm line 2643 thread 2.
cannot remove directory for C:/Users/user/AppData/Local/Temp/aVgMQeKit5: Directory not empty at C:/perls/5.38.2.2_PDL/perl/lib/File/Temp.pm line 2643 thread 2.
cannot remove directory for C:/Users/user/AppData/Local/Temp/Zd0oN4Rck4: Directory not empty at C:/perls/5.38.2.2_PDL/perl/lib/File/Temp.pm line 2643 thread 2.
cannot remove directory for C:/Users/user/AppData/Local/Temp/vhrKIEgxLc: Directory not empty at C:/perls/5.38.2.2_PDL/perl/lib/File/Temp.pm line 2643 thread 2.
cannot remove directory for C:/Users/user/AppData/Local/Temp/Dm2Gu2_CpE: Directory not empty at C:/perls/5.38.2.2_PDL/perl/lib/File/Temp.pm line 2643 thread 5.
cannot remove directory for C:/Users/user/AppData/Local/Temp/FLdkJPD2H9: Directory not empty at C:/perls/5.38.2.2_PDL/perl/lib/File/Temp.pm line 2643 thread 5.
cannot remove directory for C:/Users/user/AppData/Local/Temp/kg5ooXrV0_: Directory not empty at C:/perls/5.38.2.2_PDL/perl/lib/File/Temp.pm line 2643 thread 5.
cannot remove directory for C:/Users/user/AppData/Local/Temp/adjxT3yjzR: Directory not empty at C:/perls/5.38.2.2_PDL/perl/lib/File/Temp.pm line 2643 thread 5.
cannot remove directory for C:/Users/user/AppData/Local/Temp/13W7hYDERj: Directory not empty at C:/perls/5.38.2.2_PDL/perl/lib/File/Temp.pm line 2643 thread 5.
cannot remove directory for C:/Users/user/AppData/Local/Temp/fdIDlQUOj0: Directory not empty at C:/perls/5.38.2.2_PDL/perl/lib/File/Temp.pm line 2643 thread 5.
cannot remove directory for C:/Users/user/AppData/Local/Temp/dpQ5Ds4FXQ: Directory not empty at C:/perls/5.38.2.2_PDL/perl/lib/File/Temp.pm line 2643 thread 5.
cannot remove directory for C:/Users/user/AppData/Local/Temp/cLi_jcwNvD: Directory not empty at C:/perls/5.38.2.2_PDL/perl/lib/File/Temp.pm line 2643 thread 3.
cannot remove directory for C:/Users/user/AppData/Local/Temp/58iAPR1gco: Directory not empty at C:/perls/5.38.2.2_PDL/perl/lib/File/Temp.pm line 2643 thread 3.
cannot remove directory for C:/Users/user/AppData/Local/Temp/AzAoW3jSFH: Directory not empty at C:/perls/5.38.2.2_PDL/perl/lib/File/Temp.pm line 2643 thread 3.
cannot remove directory for C:/Users/user/AppData/Local/Temp/2JegrTh_YZ: Directory not empty at C:/perls/5.38.2.2_PDL/perl/lib/File/Temp.pm line 2643 thread 3.
cannot remove directory for C:/Users/user/AppData/Local/Temp/VYDJKfEUYb: Directory not empty at C:/perls/5.38.2.2_PDL/perl/lib/File/Temp.pm line 2643 thread 3.
cannot remove directory for C:/Users/user/AppData/Local/Temp/SjonnP9Qe0: Directory not empty at C:/perls/5.38.2.2_PDL/perl/lib/File/Temp.pm line 2643 thread 3.
cannot remove directory for C:/Users/user/AppData/Local/Temp/cq03TZExvS: Directory not empty at C:/perls/5.38.2.2_PDL/perl/lib/File/Temp.pm line 2643 thread 3.
cannot remove directory for C:/Users/user/AppData/Local/Temp/SOfiBP29hh: Directory not empty at C:/perls/5.38.2.2_PDL/perl/lib/File/Temp.pm line 2643 thread 4.
cannot remove directory for C:/Users/user/AppData/Local/Temp/HdbNJfPgp8: Directory not empty at C:/perls/5.38.2.2_PDL/perl/lib/File/Temp.pm line 2643 thread 4.
cannot remove directory for C:/Users/user/AppData/Local/Temp/yUPS_J7NLp: Directory not empty at C:/perls/5.38.2.2_PDL/perl/lib/File/Temp.pm line 2643 thread 4.
cannot remove directory for C:/Users/user/AppData/Local/Temp/FnKYg2rIXq: Directory not empty at C:/perls/5.38.2.2_PDL/perl/lib/File/Temp.pm line 2643 thread 4.
cannot remove directory for C:/Users/user/AppData/Local/Temp/DEYzOqMVz6: Directory not empty at C:/perls/5.38.2.2_PDL/perl/lib/File/Temp.pm line 2643 thread 4.
cannot remove directory for C:/Users/user/AppData/Local/Temp/eLRJunxzlT: Directory not empty at C:/perls/5.38.2.2_PDL/perl/lib/File/Temp.pm line 2643 thread 4.
cannot remove directory for C:/Users/user/AppData/Local/Temp/F1h9BeTpsb: Directory not empty at C:/perls/5.38.2.2_PDL/perl/lib/File/Temp.pm line 2643 thread 4.
cannot remove directory for C:/Users/user/AppData/Local/Temp/4wnIuBZitY: Directory not empty at C:/perls/5.38.2.2_PDL/perl/lib/File/Temp.pm line 2643 thread 1.
cannot remove directory for C:/Users/user/AppData/Local/Temp/4arKdhu8tg: Directory not empty at C:/perls/5.38.2.2_PDL/perl/lib/File/Temp.pm line 2643 thread 1.
cannot remove directory for C:/Users/user/AppData/Local/Temp/YQtjVwiCp6: Directory not empty at C:/perls/5.38.2.2_PDL/perl/lib/File/Temp.pm line 2643 thread 1.
cannot remove directory for C:/Users/user/AppData/Local/Temp/ZT_JEsLgrg: Directory not empty at C:/perls/5.38.2.2_PDL/perl/lib/File/Temp.pm line 2643 thread 1.
cannot remove directory for C:/Users/user/AppData/Local/Temp/AG5YLIbUub: Directory not empty at C:/perls/5.38.2.2_PDL/perl/lib/File/Temp.pm line 2643 thread 1.
cannot remove directory for C:/Users/user/AppData/Local/Temp/Twn_Zunm6q: Directory not empty at C:/perls/5.38.2.2_PDL/perl/lib/File/Temp.pm line 2643 thread 1.
cannot remove directory for C:/Users/user/AppData/Local/Temp/fwpW2oGrH_: Directory not empty at C:/perls/5.38.2.2_PDL/perl/lib/File/Temp.pm line 2643 thread 1.
t\regression\multithreaded01.t .. ok
All tests successful.
Files=1, Tests=42,  1 wallclock secs ( 0.06 usr +  0.01 sys =  0.08 CPU)
Result: PASS