There (will be) the possibilty to cast mutliple votes in a single vote-msg
(ballot), when multi-choice polls are introduced later. There were just too
many things call vote/votes and it was getting confusing in my own head. So the
msg type for messages that contain votes is now "ballot".
smb_voted_already() now returns uint16_t (instead of BOOL), returns the votes
of the user (for polls) or just 1 for up/downvotes of msgs.