Set vote ended to true before SuccessAction().

Avoids things like:
Palladium: [ikinz]!exit
* Palladium Poll: Exit this game? [END:SUCCESS]
* Palladium exiting game
* Palladium Poll: Exit this game? [END:FAILED]
Palladium: [ikinz]!vote 1
Take some measures to prevent trollvoting.

If you have a player and a bunch of specs, the player's votes pass
automatically, but if a spec calls a vote it needs two votes to pass
instead of one.
Account for commands send in private messages too.
Merge pull request #41 from db81/voting_fixes

Voting fixes