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

Forcing a to 1.0 in DrawPixels() was a problem with blending.  It's better to upload the actual alpha, e.g. for block transfers.  Would actually like to upload stencil but I have a feeling performance will be horrible in some games.

Also fixes normal handling in software transform to match hardware transform better.

Then I went ahead and cleared the stencil and depth to 0, except on FBO creation where it uploads.  I'm hoping this doesn't cause any glitches... it may theoretically help "read framebuffers to memory" since it will destroy texture data a tiny bit less often.

-[Unknown]