Added crate object. Modified MoveSpider script.

I modified the MoveSpider script. Now a spider object with the
MoveSpider will function if the spider has a rotation of 0, 90, 180 or
270 degress. Thus, it can now be placed on many more walls and function
correctly.

I also added a crate object. I placed some crates and barrels around in
level 1.
Intermediate step
Intermediate 2
Merge pull request #14 from christiansandtveit/Christian-Working-Branch

Added crate object. Modified MoveSpider script.