Instead of setting the level to be flipped from the level file, it is now passed...

Instead of setting the level to be flipped from the level file, it is now passed through the world.
This way we can make a level designed to be played the two ways, and then the put them in the world map one after the other.
I have played the castle level flipped, and I've to say it is soo damn cool! It is like you were playing a completely different level.

It is also possible to set levels to be flipped by using --debug (this will be temporary).

SVN-Revision: 1535