Fix for camera problems caused by issue #181 (fix for issue #66 issue fi...

Found the problem:

```actionscript
				if (cam.target == null) 
				{
					cam._flashSprite.x = cam.x + cam._flashOffsetX;
					cam._flashSprite.y = cam.y + cam._flashOffsetY;
				} else 
				{
					cam._flashSprite.x = cam.x + (width >> 1);
					cam._flashSprite.y = cam.y + (height >> 1);
				}
```

This is the fix for the fix66 + zoom not working.

If i transform it into this:

```actionscript
				if (cam.target == null) 
				{
					cam._flashSprite.x = cam.x + cam._flashOffsetX;
					cam._flashSprite.y = cam.y + cam._flashOffsetY;
				} 
```

Everything seems to be working (all HaxeFlixelDemos i tested and the camera tests + zoom i have).

Since that code inside condition `if (cam.target == null)` only have effect with fix66 (because that fix updates _flashOffsetX and offsetY), and that fix only works without camera follow, its highly likely that nothing is affected by this check - meaning i think it is really fixed this time.

Anyways, focusOn() method is still not working because of the fix 66, thats something to have in mind.