added secondary weapon, the missile launcher.
TODO: make it collide with stuff
moved missile target reaching check to separate method
cleaned code
Merge branch 'master' of https://github.com/Stopa/Mobile-Defence-Fortress
Deleted old file
Changed structure of files
Created Orbital Defence

Not yet implemented
Fixed an error
fixed bug in quadtree.retrieve

returned array of potential colliders no longer contains duplicates
Quadtrees now process Stage's children. +  Swarm refactoring

The QuadTree structure checks each child of the Stage to see if it's a
Destructible. If yes, it gets added to the quadtree.

* Removed the "Game.colliders" array, as this purpose is now served by
the Stage.children array.
* Modified related classes to fit the changes.
Merge branch 'master' of https://github.com/Stopa/Mobile-Defence-Fortress

Conflicts:
	assets/javascripts/actor/Enemy.js
	assets/javascripts/collision/Collision.js
Temporary Orbital Defence
FFS GIT
Orbital Defence
Merge branch 'master' of https://github.com/Stopa/Mobile-Defence-Fortress
Merge remote-tracking branch 'origin/master' into gh-pages