Looking into fixing rendertargets
small testing framework; but too tired.
hooked up legacy GL to test FBOs.
more tweaking with fbo
removing spriteconfig asset
adding new image struct; replacing asset texture fields
stubbing out new texture funcs
experimenting with new texture ideas
patching up fixedarray
texture refactor

support RenderTargets
removing old sampler2d
FixedArray ignores requests to allocate 0 elements
font tweaks to use the new renderer
cleanup of old image code; now using new interface
removing old TextureParameters and cleaning up interface
add basic support for tracing allocations
cleanup old texture use
additional texture cleanup and logging
update font-stash (uses userdata for textures)
tweaking preprocessors for GLES/mobile
update pegasus ref