DSound: use DSound notifications to produce sound.

Pretty straightforward; IDirectSoundNotify lets you register for
notifications after a certain amount of sound has played, so use that
instead of depending on Update() notifications from the CPU thread.

Also, while I'm here, reduce the buffer size by a factor of 4; this seems
to reduce the latency, although the difference is sort of subtle.
Gameini updates.

Updates game inis for Serious Sam: Next Encounter (gc), CAPCOM VS. SNK 2
EO (gc), Baten Kaitos Origins (gc), Baten Kaitos Eternal Wings and the
Lost Ocean (gc), Sonic Adventure 2 Battle (gc), Sonic Riders (gc), Sonic
Adventure DX (gc), Mini Ninjas (wii), The Legend of Zelda Skyward Sword
(wii).
Fixes issues 7146 and 6440.
More updates.

For 007: Agent Under Fire (gc), SHADOW THE HEDGEHOG (gc), NFL Street
(gc), NFL Street 2 (gc), NBA STREET V3 (gc).
Fixes issues 7224, 7216 and 7238.
GCMemcard: fix edge case of adding to a fragmented memcard.

allocates last block of memcard, and then wraps around, instead of attempting to write past the end of the card
Jit64: implement tw/twi more accurately

Fixes issue 7253.
Merge pull request #290 from Linktothepast/gameini_updates

Gameini updates.
Move the #pragma once header guard before the includes in Statistics.h in VideoCommon.
Disable SDL input on Windows.
Remove SDL from Externals.
VideoCommon: fix indirect texture coordinate computation in TEV.

Even if an indirect texture stage doesn't actually sample a texture, we
still need to emit the relevant math.

Fixes Issue 7092.
VideoCommon: correctly compute whether an indirect texture stage is active.

This is consistent with the implementation in PixelShaderGen.
Enables usage of GLSL textureSize on Qualcomm v66.

Qualcomm's v66 drivers have a working textureSize() function now.
Enable usage of it.
ogl: fix signed vs unsigned comparison warning
ShaderGen/D3D: inline centroid
ShaderGen: merge early-z blocks of ogl+d3d
ShaderGen: use cbuffers for D3D
ShaderGen: inline constant shaders
PixelShaderGen: drop fmod as it isn't used any more
PixelShaderGen: extract iround
ShaderGen: make clipPos readonly