grep 2.5-1 sets matcher incorrectly when program prefix in use

[Joe Buehler]

Installing grep 2.5-1 with --program-prefix=g does not correctly
select the proper matcher (grep, egrep, fgrep) because the code
in main() that looks at argv[0] is not taking into account the
transformation on the program name that --program-prefix implies.

Also, looking at the code in main(), it appears that the win32-specific
code that massages argv[0] should be BEFORE the argv[0] checks.
--
Joe Buehler