added assimp library
fix compilation for msvc 11
fix mingw-64 compilation
added depth write to gl functions
added render state
refactor gpu program again
nest shader type in gpu program
remove shader source files
gpu program and params
minor bug fixing
gl draw arrays
added surfaces to mesh builder
added render mesh method
float param for gpu program
fix default render state, draw mesh
multiple gpu program attributes with the same tag
setup working directory for msvc
link boost python to core library
neginecore python module
update shared library build