Examples: GPGPU Birds BufferGeometry

- replaces old geometry with a buffergeometry
- this helps speed up initialization times
- also renamed SimulatorRenderer -> SimulationRenderer
Examples: GPGPU Birds update BufferGeometry addAttribute method
Examples: GPGPU Bird, removed redundent variables in shaders
Merge branch 'gpgpu_birds_buffer' of https://github.com/zz85/three.js into dev

Conflicts:
	examples/webgl_gpgpu_birds.html