Added param interfaces for Physics2DDevice create methods
Added param interfaces for Physics2DDevice create methods
Modified feedback according to comments

I changed the parts from the comments. The interface for the broadphase has also been used as suggested but I had to modify the Physics2DBoxTreeBroadphase for it to work.
Removed validate from Physics2DBroadphase

As discussed, I removed the validate method from the Physics2DBroadphase interface and Physics2DBoxTreeBroadphase class.
Merge pull request #37 from dkorbar/master

Added interfaces for the different params parameters of the Physics2DDevice create methods