- Self-reference bug

- Refactoring/clean-up of code
- Dependency tracking of aliased cells
- Various resolution errors
- Rewriting of ranges when columns/rows are inserted/removed
- References to aliases keep their units.

src/Mod/Spreadsheet/App/PropertyColumnWidths.cpp

@@ -155,3 +155,14 @@ PyObject *PropertyColumnWidths::getPyObject()
     }
     return Py::new_reference_to(PythonObject);
 }
+
+void PropertyColumnWidths::clear()
+{
+    std::map<int, int>::const_iterator i = begin();
+
+    while (i != end()) {
+        dirty.insert(i->first);
+        ++i;
+    }
+    std::map<int,int>::clear();
+}