Remove unused tile data and collision routines

[hexus]

Some data and code is irrelevant to the final solution, left over from experimentation. Remove it.

[hexus]

Half-way there; the regular collision routine has been cleaned up.

[hexus]

Should've clarified what needed removing here...

Edit: According to the diff between 0.1.1 and 0.1.0, ignormals are unused.