Add quattor-configure, quattor-unconfigure and quattor-list commands

These are copied from TCD's quattor_commands.tpl to begin the implementation of
https://trac.lal.in2p3.fr/Quattor/wiki/Development/Scrum/CommandRenaming
Merge pull request #6 from jrha/master

Add quattor-configure, quattor-unconfigure and quattor-list commands, for user-friendliness.