Add type hints to python for class constructors

* We enforce default and copy constructors where possible, this isn't very
  pythonic but we can't use copy.deepcopy on our types.
* The structs that have specialised constructors e.g. FloatVector or Subresource
  also have those documented though we have no way to enforce it.

qrenderdoc/Code/pyrenderdoc/ext_refcounts.h

@@ -87,5 +87,10 @@ fail:
 template <>
 inline SDFile *MakeFromArgsTuple<SDFile>(PyObject *args)
 {
+  if(!SWIG_Python_UnpackTuple(args, "new_SDFile", 0, 0, 0))
+    SWIG_fail;
+
   return new SDFile();
+fail:
+  return NULL;
 }

qrenderdoc/Code/pyrenderdoc/qrenderdoc.i

@@ -114,6 +114,9 @@ TEMPLATE_FIXEDARRAY_DECLARE(rdcfixedarray);
   static int capviewer_init(PyObject *self, PyObject *args) {
     PyObject *resultobj = 0;
     ICaptureViewer *result = 0;
+    
+    if(!SWIG_Python_UnpackTuple(args, "new_CaptureViewer", 0, 0, 0))
+      return -1;
 
     result = new PythonCaptureViewer(self);
     resultobj = SWIG_NewPointerObj(SWIG_as_voidptr(result), SWIGTYPE_p_ICaptureViewer, SWIG_BUILTIN_INIT | 0);