Tutorial finished. Some levels authored.

- The tutorial is finished and a bit polished.
- The first 10 levels are created.
- Added a script for the story.
- Added a method for creating text inside levels.
- Ignore tedious Thumbs.db files.

Note to self:
I should start thinking about making smaller change lists. Making big
commits defeats the purpose of source control... :<
ALPHA version of the game.

- Final scene with explanation and win screen.
- Extra levels to make it more complete.
- Final assets.
Initial release version of the full game.

- Added minimalistic music score.
- Added sound effects for jump, teleport, colour change and fall down.
- Polish and small changes.