Implementing new collision detection.

Compiling fine but many collisions being missed.
Operational wall face collisions.

Corners and zero velocity components still not working, along with
diagonal walls.
Finished corner collisions and zero velocity components.
Partially implemented diagonal collisions.
Continued implementing diagonal collisions.

Straight diagonal and down/right now work. Only down/left to go.
Finished implementing diagonal collisions.

Fixed down/left and returned rmSpeedWall1 to its original design.
Tidied up collision implementation.

Changed from using hspeed, vspeed and resetting position every frame to
using xvel,yvel and updating in collision check. Also tidied up debug
arrows and redundant normal_time code.