Part: GeometryDefaultExtensions template

========================================

Generalisation of code for a default geometry extension in the form of a template.

Default geometry extensions provide a standard interface for an extension having a single stored value (e.g. one int or one string).

Python implementation must be provided separatedly.

src/Mod/Part/App/GeometryStringExtensionPyImp.cpp

@@ -27,7 +27,7 @@
 # include <sstream>
 #endif
 
-#include "GeometryStringExtension.h"
+#include "GeometryDefaultExtension.h"
 
 #include "GeometryStringExtensionPy.h"
 #include "GeometryStringExtensionPy.cpp"
@@ -38,7 +38,7 @@ using namespace Part;
 std::string GeometryStringExtensionPy::representation(void) const
 {
     std::stringstream str;
-    str << "<GeometryStringExtension (" << getGeometryStringExtensionPtr()->str << ") >";
+    str << "<GeometryStringExtension (" << getGeometryStringExtensionPtr()->value << ") >";
     return str.str();
 }
 
@@ -60,7 +60,7 @@ int GeometryStringExtensionPy::PyInit(PyObject* args, PyObject* /*kwd*/)
     PyErr_Clear();
     char *pstr;
     if (PyArg_ParseTuple(args, "s", &pstr)) {
-        this->getGeometryStringExtensionPtr()->str=pstr;
+        this->getGeometryStringExtensionPtr()->value=pstr;
         return 0;
     }
 
@@ -74,12 +74,12 @@ int GeometryStringExtensionPy::PyInit(PyObject* args, PyObject* /*kwd*/)
 
 Py::String GeometryStringExtensionPy::getValue(void) const
 {
-    return Py::String(this->getGeometryStringExtensionPtr()->str);
+    return Py::String(this->getGeometryStringExtensionPtr()->value);
 }
 
 void GeometryStringExtensionPy::setValue(Py::String value)
 {
-    this->getGeometryStringExtensionPtr()->str = value.as_std_string();
+    this->getGeometryStringExtensionPtr()->value = value.as_std_string();
 }
 
 PyObject *GeometryStringExtensionPy::getCustomAttributes(const char* /*attr*/) const