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)

#!/bin/sh

hg init rep
cd rep
mkdir dir
touch foo dir/bar
hg -v addremove
hg -v commit -m "add 1" -d "1000000 0"
cd dir/
touch ../foo_2 bar_2
hg -v addremove
hg -v commit -m "add 2" -d "1000000 0"