Add full rotation to rotatable entities

[Jigoku]

Instead of using 0,1,2,3 for 90 degree rotation, allow R+SCROLL bind to rotate 0-360 degrees.
This will allow more variety for placing entities such as props.

[Jigoku]

This was implemented pretty easily, however, collisions are a problem for selecting entities. Will need to add proper polygonal collision for rotated entities.

[Jigoku]

Note; Look into existing collision libraries.