Polish, fix and otherwise improve the video plugin configuration dialog:

- Add some info about a backend's feature set (MSAA, Real XFB, EFB to RAM, ..) to VideoConfig
- Gray out options if they aren't supported by the backend or if changing them doesn't affect anything (e.g. changing STC mode if STC is disabled)
- Allow signed bytes for D3D11. Not sure if this causes glitches, but it should work
- Call wxEvent.Skip() in the event function handlers, not sure if this fixes any bugs but the old code definitely caused bugs during development of this patch
- Fix a memory leak in the configuration dialog if D3D11 is used
- Other minor stuff that doesn't need to be mentioned or which I forgot

git-svn-id: https://dolphin-emu.googlecode.com/svn/trunk@6450 8ced0084-cf51-0410-be5f-012b33b47a6e

Source/Core/VideoCommon/Src/TextureCacheBase.h

@@ -97,8 +97,6 @@ private:
 	typedef std::map<u32, TCacheEntryBase*> TexCache;
 
 	static TexCache textures;
-
-	virtual bool isOGL() { return false; }	// Hacks for TextureDecode_real support
 };
 
 extern TextureCache *g_texture_cache;