combat phase refactor

- redone mapmode offsets to fix a problem with 2x mode being not
centered (still a problem at lower right corner, only fixed upper left)
- redone mapmode switches (in mouse function) so that mapmode 3/4 aren't
actually drawn on top of 1/2

- refactoring of combat, adding phases. Initiative only counts within
same phase
- player and monster turn moved to their own function
- player in phase 3 just to be with the monsters, phase switching not
yet implemented
- mouseover initiative list still not enabled

Can't add more detail because Github tells me diff too large :(