D3D: Implemented context state caching

This avoids most of the redundant API calls.
D3D: Removed cull mode changes for lines and points

Fixed include order and whitespace
D3D: StateManager m_current and m_pending are now value-initialized
D3D: Fixed StateManager member function name case
D3D: Fixed debug validation error

A texture was still being bound when OMSetRenderTargets is called.
State manager resource cache must be flushed to unbind it.
This fixes The Last Story cut scene rendering.
DolphinQt: Silence -Wshadow warnings.
VolumeHandler: Return success value
Merge pull request #1503 from kayru/d3d_optimization_cache

D3D: Filter redundant API calls by caching state in StateManager
Merge pull request #1682 from JosJuice/volumehandler-return

VolumeHandler: Return success value
Enable block-linking with MMU.  Blocks that cause an ISI exception are not linked.
Merge pull request #1684 from skidau/mmu-blocklink

Enable block-linking with MMU
Merge pull request #1679 from rohit-n/shadow-qt

DolphinQt: Silence -Wshadow warnings.
Quick hack to check if fastmem+memcheck is worthwhile.
Fix assertion error.
Correctly turn off fastmem for quantized load/store.
More complete implementation.
More fixes.