Base: misc patches

Convenience macros/function (in Interpreter.h)

* FC_PY_GetObject/Callable(), look for callables in a python object,
  which will be used in future patch to improve performance in various
  python observer/features.

* pyCall(WithKeywords)(), helper function to invoke the callable

Matrix4D:

* hasScale(), check if there is any scale in the transformation. If so,
  further check if the scale is uniform or not. This will be used in
  future patch for Part::TopoShape to decide which type of transform to
  apply.

Placement:

* translate/rotate(), new convenience API

Rotation:

* isSame/multiVec(), new convenience API

Polygon2d:

* Intersect(), GetCenter(), new convenience API.

FlagToggler:

* New class for exception safe flag toggling, similar to StateLocker
  but with template (actually, FlagToggler is added earlier by me).

BitsetLocker:

* New class for exception manipulation of a std::bitset variable.

src/Base/MatrixPyImp.cpp

@@ -238,6 +238,14 @@ PyObject* MatrixPy::scale(PyObject * args)
     Py_Return;
 }
 
+PyObject* MatrixPy::hasScale(PyObject * args)
+{
+    double tol=0;
+    if(!PyArg_ParseTuple(args, "|d", &tol))
+        return 0;
+    return Py::new_reference_to(Py::Int(getMatrixPtr()->hasScale(tol)));
+}
+
 PyObject* MatrixPy::unity(PyObject * args)
 {
     if (!PyArg_ParseTuple(args, ""))     // convert args: Python->C