Embed stubsgen.py and automatically generate stubs into user folder

* We create both a stubs folder for each specific version, and a 'latest' that
  is updated by newer RD versions.
* For development, the stubs will be regenerated any time the git commit hash
  changes for development builds.

qrenderdoc/Code/pyrenderdoc/PythonContext.h

@@ -65,6 +65,8 @@ public:
                             rdcarray<rdcpair<rdcstr, PyObject *>> &args);
   static void FreePyArgs(rdcarray<rdcpair<rdcstr, PyObject *>> &args);
 
+  static void GenerateStubs(const rdcarray<rdcstr> &extraPaths);
+
   bool CheckInterfaces(rdcstr &log);
 
   QString versionString();