[WIP][CR] Scrolling Combat Text

On screen animated display of the dealt/received damage to/from creatures.
(Probably best known from various MMO's)

Damage numbers will float in the direction you hit/got hit from. They are visible for 5 ticks.

Known Issues:
No tiles support yet, only Curses/SDL. Will have a look at that once it's done.
Messages in east/west direction can get a little tangled together.
Terrain redrawing code has use u_see() to prevent unseen areas to become visible.
0 damage to creatures should not be displayed.
Ranged damage from turrets gets displayed twice.

PS: Fixed some things with the hit and weather animation code as well.