Version 6.7.3

Version 6.7.3

- change: use del instead of rm.exe in the project's makefile
- fix: Generated makefiles have error for dll projects
- fix: gdb annotation infos are not correctly displayed
- fix: the symbol completion option for ']' doesn't work
- experiment support for clang (msys2 64bit build) 
issues for clang:
- gdb used by clang dosen't support path name without non-ascii characters
- clang doesn't support encoding arguments
- Parser can't correctly parse libc++ header files (support will be done in the QT version of devcpp)