Fixed some memory leaks.

app/lib/surface/CocoSprite.coffee

@@ -302,7 +302,7 @@ module.exports = CocoSprite = class CocoSprite extends CocoClass
     [@imageObject.x, @imageObject.y] = [sup.x, sup.y]
     @lastPos = p1.copy?() or _.clone(p1)
     @hasMoved = true
-    
+
   updateBaseScale: ->
     scale = 1
     scale = @thangType.get('scale') or 1 if @isRaster
@@ -331,9 +331,9 @@ module.exports = CocoSprite = class CocoSprite extends CocoClass
           @imageObject.scaleY *= @thangType.get('scale') ? 1
         [@lastThangWidth, @lastThangHeight] = [@thang.width, @thang.height]
       return
-    
+
     scaleX = scaleY = 1
-      
+
     if @thangType.get('name') in ['Arrow', 'Spear']
       # Scales the arrow so it appears longer when flying parallel to horizon.
       # To do that, we convert angle to [0, 90] (mirroring half-planes twice), then make linear function out of it:
@@ -791,4 +791,4 @@ module.exports = CocoSprite = class CocoSprite extends CocoClass
     p.removeChild @healthBar if p = @healthBar?.parent
     @imageObject?.off 'animationend', @playNextAction
     clearInterval @effectInterval if @effectInterval
-    super()
+    super()

app/lib/surface/SpriteBoss.coffee

@@ -161,6 +161,7 @@ module.exports = class SpriteBoss extends CocoClass
     thang = sprite.thang
     delete @sprites[sprite.thang.id]
     @spriteArray.splice @spriteArray.indexOf(sprite), 1
+    @stopListening sprite
     sprite.destroy()
     sprite.thang = thang  # Keep around so that we know which thang the destroyed thang was for
 

app/models/ThangType.coffee

@@ -30,7 +30,7 @@ module.exports = class ThangType extends CocoModel
   isFullyLoaded: ->
     # TODO: Come up with a better way to identify when the model doesn't have everything needed to build the sprite. ie when it's a projection without all the required data.
     return @get('actions') or @get('raster') # needs one of these two things
-  
+
   getActions: ->
     return {} unless @isFullyLoaded()
     return @actions or @buildActions()
@@ -62,7 +62,9 @@ module.exports = class ThangType extends CocoModel
     @options = @fillOptions options
     key = @spriteSheetKey(@options)
     if ss = @spriteSheets[key] then return ss
-    return key if @building[key]
+    if @building[key]
+      @options = null
+      return key
     @t0 = new Date().getTime()
     @initBuild(options)
     @addGeneralFrames() unless @options.portraitOnly
@@ -159,6 +161,7 @@ module.exports = class ThangType extends CocoModel
     @spriteSheets[key] = spriteSheet
     delete @building[key]
     @builder = null
+    @options = null
     spriteSheet
 
   onBuildSpriteSheetComplete: (e, data) ->