rewrite revert command. fix issues 93, 123, 147. new version does these things: - saves backup copies of modified files (issue 147) - prints output like other commands, and errors when files not found (issue 123) - marks files added/removed (issue 93)

syntax: glob

*.elc
*.orig
*.rej
*~
*.so
*.pyc
*.swp
*.prof
tests/*.err
build
dist
doc/*.[0-9]
doc/*.[0-9].gendoc.txt
doc/*.[0-9].{x,ht}ml
MANIFEST
patches
mercurial/__version__.py

syntax: regexp
^\.pc/