More functional changes

+ Got rid of unnecessary code that was slowing down the rendering -
Optimized to be able to handle a vast slew of minions without any
performance hits.
+ Fixed a bug causing climbers to break on delete.
+ Added a "Delete" mode for tower pieces that will delete a tower, and
drop the rest of the tower to accommodate.
+ Added modes for left clicking. Currently only have delete/activate
mode. Right clicking when in any other mode reverts back to the basic
activate mode.
+ Randomized Z start of spawning climbers.