Identified where to put collision checks. Added comments and boolean flags.
Added dependencies on header files, so it recompiles appropriate sources when
one changes.
Fixed condition to disallow non-attacking buildings.
Added methods to add and remove SparCraft:Unit and to check collisions against
buildings. Very crude first try.
Keep map up-to-date with units. Check for collisions when generating moves.
Discard if it collides.