Configuration manager sketch
Configuration callback
Rvalue passed as argument for configurations
IRenderer context abstraction for window size + Better config manager
Save to file configurations
Configuration serialization human readable / editable
Json serialization functions
Load and save and callback ok for config file
Window to center of screen on resize
rvalue reference removed
Merge pull request #170 from Another-Game-Engine/configuration_file

Configuration manager - Load and Save conf files
Unused added
Warning removed + cast
Warning cleaning
Merge pull request #171 from Another-Game-Engine/utils_and_warnings

Utils and warnings
Avance on texture and PBO implementation
Merge branch 'master' of https://github.com/PFA-OpenGL/Demoscene-OpenGL
merge with master, forget to close #155 for shader
texture and pixel buffer are impelement, need to be improve close #172 and close #173