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
UMVE: Follow-up commit for plugin system
UTIL: Small style changes
OGL: Follow-up commit for UMVE plugin system
MVE: More comments in bundle.h
MVE: Fixed EXIF parser for Big-Endian byte order
MATH: Fixed typo in vector class
UTIL: Introduced exception on failed string conversion