Added -s --soft arguments as well.
Default roll-back one with HEAD^ and only using ~ if commit count more than 1.
Added auto complete.
Updated documentation.
Attitude adjustment: don't throw errors and say NO as suggested in #114, have a can do attitude instead, leave the errors up to git to report.
-h option allows you to undo the last commit without keeping the
changes in the local working directory. Use with care.
Updated documentation to include new option.
Wiping out previous commits is error prone. Most people probably want to edit their
changes and commit again. Modified behavior so that when undoing a commit, changes
are left in the user directory unstaged.
