[fix] re-arrange check for optional slots. remove old commetns.
move a null check to the top, it should only occur if the schemtaic
lua is messed up.


Change-Id: Ia23a4440ff7cb07d6fa59af9838b6e6e843b4922
[fixed] npc type at imperial vs gungan battle
[added] an observer to trigger reinforcements to spawn for both sides

Change-Id: I821d93bb54ae4e1e4be486eebae096fe72b0960f
Merge "[fix] re-arrange check for optional slots. remove old commetns. move a null check to the top, it should only occur if the schemtaic lua is messed up." into unstable
Merge "[fixed] npc type at imperial vs gungan battle [added] an observer to trigger reinforcements to spawn for both sides" into unstable