Add find command
Add find recursively command
Pipe list command into find command for highlighting
Ignore invalid paths when executing git commands

Also adds highlighting to multigit output when running commands, but at the
expense of showing the command executed
Update README.md
Merge remote-tracking branch 'origin/master'
Add a help message when no arguments are present

Fix #5
Merge branch 'master' into tidy
Separate existence checks and warnings
Integrate new changes with `tidy' syntax