Fix ValueError when /var/lib/yum/groups/installed is empty. BZ 971307
 Fix 'yum updateinfo list all new-packages' traceback. BZ 1072945

And make 'list' and 'info' indicate if the package is installed.
Make yum quit when an invalid option is provided with --setopt.
 Add all the weak deps. tags via. prco.

 Edit's by James Antill, note that we aren't supplying an API above
returnPrco() atm.
Fix traceback when history files don't exist and user is not root.
Make utils.get_process_info() respect executable names with spaces.
Refactored utils.get_process_info() to make parts of it reusable.