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/Rotation.cpp

@@ -396,6 +396,18 @@ bool Rotation::isSame(const Rotation& q) const
     return false;
 }
 
+bool Rotation::isSame(const Rotation& q, double tol) const
+{
+    Vector3d v(0,0,1);
+    return std::fabs(multVec(v).GetAngle(q.multVec(v))) < tol;
+}
+
+Vector3d Rotation::multVec(const Vector3d & src) const {
+    Vector3d dst;
+    multVec(src,dst);
+    return dst;
+}
+
 void Rotation::multVec(const Vector3d & src, Vector3d & dst) const
 {
     double x = this->quat[0];