util._matcher: unify pattern normalization
This should fix
issue347.
It also highlights one issue with the directory walking code when
you have an --include pattern that matches the end of a filename.
This is fixed by the next patch.
#!/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