x86jit: Support fpu rounding modes for mul, etc.

Fixes Gods Eater Burst loading PSP savedata, but can no longer load old
savedata.
x86jit: Implement cvt.w.s.

Not really used that often, anyway, but easy enough and good for testing
that we set the rounding mode correctly.
armjit: Respect the rounding mode for mul/etc.
Add a frontend option for GEB saves.

May also affect performance, so can be disabled for that.
x86jit: Maintain the rounding mode always.

This should be less often than doing it per block that uses fpu, unless
the game doesn't use fpu much at all.
(Partially) slip thin3d underneath DrawBuffer.
Start hooking up D3D
Hook up DX9 backend. Not really working though, it seems.
Convert more UI code to Thin3D
D3D9: Don't crash on bad vertex formats.
D3d cleanups and improvements
Bit more d3d stuff. Can't get depth right, pretty sure it's the projection matrix calc.
armjit: Maintain rounding mode throughout jit.
Get it running on Android again
Buildfix Linux.
Provide more info to thin3d d3d init
Merge pull request #6762 from unknownbrackets/fpu-rounding

Handle fpu rounding mode at least in jits
Merge pull request #6767 from unknownbrackets/thin3d

Buildfix Linux
Disable OpenGL debug log output
Merge branch 'thin3d' of github.com:hrydgard/ppsspp into thin3d