Runscript 1.0 Beta 6

A few important features, a few fixes.

Changes since last beta:

• Support for external shells! Declaring a target in this manner: [target:phase] /path/to/sh will execute /path/to/sh <temp_file> <positional args> when you run that phase. An external shell can be chosen for all targets with the ::default-shell /path/to/sh file-wide option.
• Shell-style functions are now supported. While not necessarily directly useful in scripts, this allows more shell scripts to be sourced successfully.
• The CLI has received special attention and should be more robust
• if statements are now implemented properly.
• $* parameters have been implemented, which evaluates positional parameters as shell words
• The old-parser will not crash on you if you're using that feature