Shader Nodes:
* Use unified node sizes, as already was done with compositor nodes. Only Mapping node uses a custom size. This way we don't have too small nodes on creation anymore.
* Don't show Script Category for Blender Internal nodes. 

git-svn-id: https://svn.blender.org/svnroot/bf-blender/trunk/blender@56954 954f8c5b-7b00-dc11-b283-0030488c597c