Replaced include_directories to target_include_directories. (Resolves #77)
Added new OpenGL Core Profile renderer (RENDER_OPENGL_CORE) with sample. Requires GLEW and GLM. (GLEW - OpenGL extension wrapper)
Added ability to remove GLFW as dependency, but OpenGL samples will not build without it. (May be needed if GWork shall be used with another system-specific functional provider, like Qt)
include_directoriestotarget_include_directories. (Resolves #77)RENDER_OPENGL_CORE) with sample. Requires GLEW and GLM. (GLEW - OpenGL extension wrapper)README.mda little.