tests: make timezone in diff output glob-ed for portability
Before this patch, some tests using external "diff" command via
extdiff extension fail on Solaris, because system standard "diff" (=
/usr/bin/diff) on Solaris doesn't display timezone for timestamp of
each files in diff output.
This patch makes timezone in external diff output glob-ed for
portability of tests, and adds check-code.py a rule to detect such
$ hg init
$ echo 123 > a
$ hg add a
$ hg commit -m "first" a
$ mkdir sub
$ echo 321 > sub/b
$ hg add sub/b
$ hg commit -m "second" sub/b
$ cat sub/b
321
$ hg co 0
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ cat sub/b 2>/dev/null || echo "sub/b not present"
sub/b not present
$ test -d sub || echo "sub not present"
sub not present