[Nouveau] [Patches]mesa/nv30: Diverse set of patches that improve NV3x render quality

[Roy Spliet]

For all these patches I'd say: testers are welcome. The first three patches seem good enough to push as we speak IMHO (so if you agree, go ahead!), whereas for the fourth I don't know if this is the desired way to fix. The result of these four patches is that NV34 gives a nearly-correct desktop experience, where only some fading animations appear broken. It's quite useable now!

[1/4]: Fixes nearly all piglit vertprog testcases, due to it now being able to pass the results on to the fragment shader. 
[2/4]: Fixes shader compiler assertion errors: src[1] was uninitialised or filled with rubbish. Fixes several piglits.
[3/4]: as it says
[4/4]: Avoids the case where the framebuffer (?) is assumed to be swizzling and linear. Due to the current OR-logic this results in a type of 0x3, which simply does not exist in NV30 hardware. A better fix can be proposed, but as far as I know this does no harm even if the bug I hit was only due to a broken mesa setup.