Fix sprite resize ratio
Fix sprite resize ratio

- This was actually a bug that @agmcleod found after looking over the whitespace changes.
- The `undefined` was changed to a string to correct the typeof() statement, but the logic was broken anyway! :)

rlugojr/melonJS,gopalindians/melonJS,srbala/melonJS,melonjs/melonJS,srbala/melonJS,rlugojr/melonJS,gopalindians/melonJS,rlugojr/melonJS,MarkoIvanetic/melonJS,TukekeSoft/melonJS,srbala/melonJS,MarkoIvanetic/melonJS,TukekeSoft/melonJS,melonjs/melonJS,gopalindians/melonJS,TukekeSoft/melonJS