Lots of changes:

- Created a 'ProgressBar' class that can be used
  anywhere.
- Added custom loading screen with cute background.
- Remade the tilesets - game's way cuter now.
- Fixed some bad things on the second level
- Some meta changes for the node webkit builder
Now the load screen shows a text saying which things we have loaded. Also, right before anything happens, we show a message to assure the game will be loaded (a must-have on slow internet connections)