Removed useless mutex use in Renderer

Change-Id: I05f4d519865f6c8bb7ba8c9089185546fa222db7
Reviewed-by: Sean Harmer <sean.harmer@kdab.com>
TechniqueManager

RenderTechnique are indexed by a pair composed of the Effect frontend and the
technique name.

Change-Id: Ie4dd5388ca7fc87905cef196a6e23d7941389114
Reviewed-by: Sean Harmer <sean.harmer@kdab.com>
Added TechniqueManager to Renderer

Change-Id: I9973a717ca41786294574baa572ca311aaf0cbc1
Reviewed-by: Sean Harmer <sean.harmer@kdab.com>