Merge branch 'v3.1' of https://github.com/sidebolt/cocos2d-iphone into v3.1

Author: slembcke

cocos2d/CCSpriteFrameCache.m

@@ -449,6 +449,10 @@ -(CCSpriteFrame*) spriteFrameByName:(NSString*)name
 
     if (!frame)
     {
+        // Check fileLookup.plist
+        NSString *newName = [[CCFileUtils sharedFileUtils].filenameLookup objectForKey:name];
+        name = newName ?: name;
+        
         // Try finding the frame in one of the registered sprite sheets
         NSString* spriteFrameFile = [_spriteFrameFileLookup objectForKey:name];
         if (spriteFrameFile) [self addSpriteFramesWithFile:spriteFrameFile];