* Added dependency tracking to the Property class.

* Added expression support to DocumentObject class.
* Added expression support to Sketcher workbench.

Conflicts:
	src/Mod/Sketcher/App/SketchObject.cpp
Reverted some fields back to Gui::InputField.

Conflicts:
	src/Mod/Sketcher/Gui/EditDatumDialog.cpp
patch to fix build on windows
merge-related fix