Rewrite handling of DTK (streaming) audio.

The primary motivation here is to make sure we submit samples from the
CPU thread. This makes sure the timing of related interrupts accurate,
and generally keeps the different kinds of audio synchronized.  This will also
allow improvements to audio dumping functionality.

The new code is also more concise because it gets rid of some duplicated
audio mixing code.
Audio mixer: remove check for ratio > 1.0.

The code actually handles this case correctly; the algorithm is linear
interpolation between the two closest samples, and the way it is written
should work correctly with any ratio.
Audio mixer: fix a couple compiler warnings.
Streaming/DTK audio: fix pausing playback.
Try to make DTK rewrite handle events the same way as the old code.
JIT: Clean up float loads and stores.

Less code is good, and this should make future changes to memory handling
easier.
JIT: Remove dead code.
JITIL: fix some unsafe loads.

I'm planning on making changes to the memory code, so I don't want this
stuff to get in the way.  The slight performance hit to JITIL isn't really
important at the moment.
JIT: Make lmw/stmw use safe load/stores.
Remove the 32-bit config platform from the VS solution and projects
Merge pull request #513 from lioncash/vs-x64

Remove the 32-bit config platform from the VS solution file
Move CoreTiming::downcount to PowerPC::ppcState.

This isn't technically the correct place to have the downcount variable, but it is similar to what PPSSPP does to gain a bit of extra speed on ARM.
We access this variable quite a bit, with each exit in a block it is subtracted from.
On ARM this required four instructions to load and store the value, while now it only requires two.

This gives an average of 1FPS gain to most games.
Examples:
Crazy Taxi: 54FPS -> 55FPS
Luigi's Mansion: 20FPS -> 21FPS
Wind Waker(Save Screen): 27FPS -> 28FPS

This seems to average a 6mhz to 16mhz CPU core emulation improvement in the few games I've tested.
Merge pull request #503 from Sonicadvance1/PowerPC-downcount

Move CoreTiming::downcount to PowerPC::ppcState.
Centralize the logging code into its own folder in Common.
Merge pull request #465 from lioncash/logging

Centralize the logging code into its own folder in Common.
AudioCommon: restore support for DTK volume setting.
Merge pull request #259 from magumagu/dtk-rewrite

DTK rewrite
Merge pull request #443 from magumagu/loadstore-cleanup

Loadstore cleanup