Minor comptime refactoring.
See merge request STJr/SRB2!1776
(cherry picked from commit dc02339cc9)
9bfc82a1 Prevent comptime.* from failing compilation
a614865d Make comptime.sh conform to POSIX and less redundant, among other improvements
b7711b2b Pass argument list directly to functions that use them; quote arguments when used.
Also makes comptime.bat work with git if able.
Development builds will now show the branch and the SHA1 hash of the revision. Also been tested to work with subversion, where it displays "Subversion r####". You know, just in case.