Allow DrawPixels (uploads) to handle alpha.

Doesn't update stencil, but at least it updates alpha.

This was fixed to 1.0 before because we had blending enabled by accident
during DrawPixels().
Use the pre-world normal in software proj mapping.

Fixes #6081.
Support reversing normals in software transform.
Upload the color/stencil buffers on FBO creation.

Fixes pausing or loading a savestate in Star Ocean (previously your
character became invisible until the screen panned.)
Clear depth buffers to zero, not 1.0f.

Memory is generally initially zeros.
Clear stencil to 0, not 1.

Memory is generally initially zeros, after all.  Fixes #5205 (or at least
improves it?) and fixes #6226.
Merge pull request #6362 from unknownbrackets/gpu-minor

Upload stencil/color on FBO create, clear depth/stencil to 0, fix software transform