Merge pull request #5 from dorkster/fp_movement

Fix power speeds and reduce shaky cam effect
Fix collision being off by half a tile

Note: This causes a bug with render order. My best guess is that there
is a round() that can be replaced with floor(), but I have no idea
where.
Use floor instead of render for Rendering.

This fixes problems as introduced by
previous commit 8c11ccf3a18031ebc8cf9b0dd1e0872e678ae8d0