Windows Register List fixes

make the rightclick work in the registerlist for all displayed registers.
The LO HI and PC registers couldn't be rightclicked previously.

Also, if you rightlick a valid row and then rightclick on the leftmost 16
pixels you'd get the popup menu for the old selection (even on invalid y
indices).

Make the "change register value"-dialog start with '0x' because otherwise
values starting with an alphabetical hexadecimal symbol will yield
be parsed as a symbol instead of a number and yield 'unknown symbol'
Implement some basic vertex previews on prim.

3D doesn't work correctly (sometimes it does...)  2D should be working.
Clean up no-inds rectange preview.
Clean up Mat3x3 etc. constness.
Fix Vec3ByMatrix44() and use it for matrix math.
Fix 3d vertex preview.
Avoid some operator overloads.

Causing ambiguity.
Cleanup, don't even need z here.
Fix vertex preview when framebuf is an odd size.

The previous stuff was wrong, just happened to work.
Move ctrl to after vblank, not before.

Tests I'd done long ago suggested this wasn't right, but we made other
timing fixes since then, and now tests are showing this is the right
order.

May improve Patapon/etc. timing, or may hurt it...
Minor simplification to ctrl buffer updates.
Include all released buttons in the latch.

Not just newly released ones.  This does appear to be how the PSP fills
this buffer - it's normally 0xffffffff.
softgpu: Only check clear mode once for depthtest.

Small, small optimization.  It's only called outside clear mode.
Update windows Memory Viewer: Attempt automatic pause/resume when dumping RAM

May need testing.
Buildfix for Qt (some platforms). Fixes #4574
MacOSX buildfix
Move PathBrowser to native
Ask the user about resuming emulation after memory dump completed.
Omit a few commands from "DL Unknown" in debug.
Switch to 59.94 fps rather than 60.