Fix find_in_path not including some file extension logic under win32.
Windows shell resolves utility path by combining PATH, the utility name and a set of file extensions from PATHEXT.
#!/bin/sh
hg
hg -q
hg help
hg -q help
hg add -h
hg add --skjdfks
hg help diff
hg help status
hg -q help status
hg help foo
hg skjdfks
exit 0