Disable SDL input on Windows.
Remove SDL from Externals.
DVD emulation: make seek timing more accurate.

Based on real measurements of a Gamecube disk on a Wii.  (If anyone else
is interested in running more tests, I can upload my code; it's a mess at
the moment.)

This isn't a complete model, but it's a step in the right direction:
in Metroid Prime, the loading times are sane, and I think I managed to do it
without breaking anything.
DVDInterface: tweak buffered reads to be a bit faster.

A read finishes when the result is complete in the drive's buffer, not
main memory.
DVDInterface: code cleanup.
Fixes games that use the MMU to page in code(Rogue Leader).

The issue was that on memory exception we wouldn't call in to PPCAnalyst and our code_block would retain the previous blocks information.
This would cause us to compile the previous blocks instructions in prior to the exception exit.
Opcode decoding: handle missing opcodes 0x88 etc.

Hardware testing shows that they do the same thing as the 0x80 family of
opcodes: they draw quads.
Video backends: fix rounding in lighting computation.

For whatever reason, the hardware doesn't do a full divide by 255, but
instead uses an approximation with shifting, similar to the way it is done
in TEV.
Possibly an OSX buildfix.
Export wii saves to the "User" directory
Use size_t in std::string operations in IniFile.cpp, not int
make IOCTL_SO_GETHOSTID more accurate on Windows
changed IOCTL_SO_GETHOSTID to remove malloc()/free() calls
account for GetIpForwardTable() returning ERROR_MORE_DATA
remove trailing whitespace
Merge pull request #374 from ToadKing/master

make IOCTL_SO_GETHOSTID more accurate on Windows
Video backends: unify xfregs/xfmem structures.

Removes the duplicate swxfregs global variable/struct from the software
backend in favor of the ones from VideoCommon.
Video backend: merge global var xfmem into xfregs.

There isn't really any reason to keep them separate.
Video backends: mass-replace "xfregs" with "xfmem".
VideoCommon: cleanup Renderer::RecordVideoMemory.
Merge pull request #269 from magumagu/swbackend-xfregisters

SW backend: use VideoCommon XFRegisters struct.