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'
Revert "More minor SasAudio optimizations"

Will reapply later in pieces.

This reverts commit cd251af345c3ed97b459b7bdb9e068a4f3e168a4.
Reapply the "duration" SasAudio optimization.
Update lang
Enable native text draw on Linux Qt.
Symbian: Should support all languages now, via native fonts.
Update submodules (Linux buildfix, lang updates.)
Remove 'lowmem' atlas. Use a 'nofont' atlas for Qt platform. Frees up ~15MB VRAM.
Symbian+Meego: Add unknown.png to package.
Fix logging missing in headless with --log.
Try to find the flash0 directory in headless.
Update tests.
Merge pull request #4566 from unknownbrackets/tests

Update tests, headless tweaks for fonts.
Oops, forgot to remove the if.
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 audio regression: Don't "WalkCurve" on state OFF
Revert a change in native that accidentally broke fbo:s