Short Fuse: Implemented the new minibomb from the Milestone 2 Design Document.

Short Fuse: Implemented the new minibomb from the Milestone 2 Design Document.

Short Fuse is a small version of Mr. Bomb, possibly his offspring. Like all
children, it runs around faster than his big relatives do but can't do any
harm.

Short Fuse will explode immediately on contact but without hurting anybody.
Instead, the explosion will throw Tux and other badguys about.

A short test level is included as well.

git-svn-id: http://supertux.lethargik.org/svn/supertux/trunk/supertux@6511 837edb03-e0f3-0310-88ca-d4d4e8b29345