Removed shading property for MeshNormalMaterial

@nraynaud do you mind double checking that I didn't break anything?

Make readRenderTargetPixels() compatible with float extensions

Updated to latest Raycaster.params

Minor cleanup in postprocessing glitch example

Minor cleanup in extrude splines example

Fixed loader md2 example

Fix for retina displays

Fix for retina displays (see #7272)

ObjectLoader continues to be broken with cached images

support WEBGL_color_buffer_float and EXT_color_buffer_half_float
also fixed a cleanup bug were the function would exit leaving the wrong buffer bound