use the "Voting" package on modules page, not a separate one

whereas all of the modules provided by this package depend on VotingAPI, and
whereas VotingAPI provides a "Voting" package on the modules page ([site]/admin/build/modules), and
whereas votingapi.module only provides 2 modules in this package, and
whereas keeping the total number of packages on the modules page is a worthy goal, and
whereas keeping all the voting-related modules on your site close to each other on that page is another worthy goal...

therefore be it resolved that the 3 modules in here move from the "Decisions" package to the "Voting" package.

patch attached. ;)