Refactor qrenderdoc to provide stable, clean and deliberate API

* Note, this API is still in-flux and beta, so there may still be some
  more changes before it's 'stable', and even then it will still be
  subject to some amount of change.
* This API is then exposed to python via SWIG bindings and hides
  internals that don't need to be visible, and means the actual API is
  easier to work with.
* We also use this API to reduce inter-dependencies between different
  windows that need to interact with each other at a high level.
* The naming is python/standard RenderDoc TitleCase method names, not
  Qt style camelCase methods.

# Conflicts:
#	qrenderdoc/Windows/PipelineState/D3D11PipelineStateViewer.cpp
#	qrenderdoc/Windows/TextureViewer.cpp

qrenderdoc/Code/qrenderdoc.cpp

@@ -142,7 +142,7 @@ int main(int argc, char *argv[])
         dir.mkpath(configPath);
     }
 
-    QString configFilename = CaptureContext::ConfigFile("UI.config");
+    QString configFilename = ConfigFilePath("UI.config");
 
     if(!config.Load(configFilename))
     {