DX9: Don't set mipfilter to aniso, it's enough to set the minfilter.

Remove erroneuos comment.
D3D9 init error reporting improved. Use "override" properly in Host.
d3d9: Make the vertex shaders more similar.
d3d9: Update some areas of the pix shader.

Will eventually want this to have the clamping etc.
d3d9: Oops, don't need this, no prescale.

Hmm, trying to reduce differences, though...
Merge pull request #6932 from unknownbrackets/d3d9

d3d9: Try to reduce distance between vertex shaders