Adjust the FPS display to be less wide.
Frontend: Add FIG and SWC files to the ROM selector.
Frontend: Show the preview of a game correctly after exiting and re-entering the ROM selector.
Frontend: Prevent a bug whereby all notes were cancelled if stereo was enabled.

The bug was due to the last value of the Stereo option not being preserved before re-entering the menu. Thus, the audio was reinitialised anew both in SDL and the Snes9x core, erasing all notes and echoes, when the menu was exited.
tile.cpp: Re-macro some code that had been expanded in DrawTile16Add.
tile.cpp: Use MIPS assembly for WRITE_4PIXELS16[_FLIPPED], part of DrawTile16.
tile.cpp: Inline WRITE_4PIXELS16[_FLIPPED] into its caller.
tile.cpp: Do not check whether a block of 4 pixels contains an opaque one.

This is counter-intuitive, but in tiles that are not fully transparent, it is more likely that a pixel is opaque. The change in this commit also eliminates one immediately-needed memory load per 4 pixels.
Remove the HeadMask and TailMask global variables.

Computing the necessary values in TILE_CLIP_PREAMBLE cuts down on the cycles needed versus a load from memory that is unlikely to be cached at the time of every access.
fxemu.cpp: Do not use GSU.pfRpix and GSU.pfPlot to pass SuperFX plotter functions around.

Based on https://github.com/libretro/snes9x-next/commit/e9c304af88fc5f69104eee9e19e6be0a9e3e9d6e by TwinAphex51224; some additional code modifications are removed.
Super FX: Remove massive amounts of indirection starting in FxEmulate.

* FxEmulate now uses fx_run directly.
* Pointers to function pointers that were formerly selected according to whether Super FX breakpoints are enabled are replaced with references to the actual array. This allows the linker to insert constant addresses.
* Super FX breakpoints are now unsupported.
Super FX: Use a local variable to hold the number of instructions left to execute.

The uses of global variables 'GSU.vCounter' and 'GSU.vInstCount' are deleted with this commit. Local variables can be kept in registers and, in that case, there are no stores to memory before each opcode function is executed.
fxinst.h: Delete unused members of 'struct FxRegs_s'.
Frontend: Add myself to credits for optimisations and fixes.
Manual: Remove a reference to a bug that has been fixed.
Manual: More edits to accurately reflect current features.
Build fix: include errno.h in menu.cpp, which uses errno.
Import "+support for SDD1 Emu added (GraphicPack not needed anymore!!)".

This commit is based on https://github.com/dmitrysmagin/snes9x4d-rzx50/commit/c1b5ea12c53c0c3b1ae083f7e999b8c6c7e010bd but includes only the code relevant to S-DD1 decompression chip emulation.
Merge branch 'firmware-2013-10-experimental' of https://github.com/Nebuleon/PocketSNES into firmware-2013-10-experimental