Initial commit

 - Add unfinished ECS framework
 - Begin creating World
Create README.md
Create LICENSE.txt
Reorganize to use Premake
Prepare for entityx usage
Change to Zlib license
Create GLFW test
Create design doc
Begin OpenGL graphics work
Continue graphics framework

- Replace SFML with GLFW (faulty rendering)
- Update premake4 file accordingly
- Create Shader class to encapsulate OpenGL shaders
- Create Camera class to encapsulate view / projection matrices
- Begin integrating graphics into ECS framework
Shader runtime error - getAttribLocation
Fix buffer / shader bugs - stable

- Add basic Buffer implementations of getBufferEnum / getBufferBindingEnum to fix pure virtual errors
- Decouple shaders from rest of graphics
- Refactor shader get/set
- Basic test working (no way to exit program)
- Improve premake4 file