Support FY_ maps

[stefanhendriks]

Like #17 mentioned the map fy_iceworld.bsp.

• bots should know they don't need to buy stuff (check if in buyzone, instead of assuming)
• there is no freezetime? if so, respect that
• there are weapons on the ground? pick those up (GOAL_WEAPON ?)

[stefanhendriks]

Spawn points in fy_iceworld are floating higher than usual, which generated #25