UMVE: allow plugins to use SceneManager
UMVE: add hello world plugin example
MVE: also load shaders from string (API change!)
UMVE: use new shader api
UMVE: have a search path for plugins/shaders

Search for shaders and plugins in several paths, using Qt Resources as a
fallback (this is especially useful for shaders).
Merge pull request #81 from Waldteufel/umve-modularity

UMVE modularity