SlyVote v1.02: Now uses the new get_index() messagebase function, if...

SlyVote v1.02: Now uses the new get_index() messagebase function, if available, for getting the message index objects when determining if a sub-board has polls (in the subBoardHasPolls() function).  get_index() is faster than iterating through all messages and calling get_msg_index() for each message.