Add "Step Prim" button, reorganize buttons a bit.
Add a stub for a vertex preview.
Format stencil and alpha tests differently.

One is the stored value on the right, the other is the vertex value on
the left.
Add a format for clearmode.
Format a few more state values.
A few more texture related formats.
Merge pull request #4162 from unknownbrackets/debugger

Add more formatting to GE debugger, cleanup, step prim