python objects, so that Gramps classes are never pickled.
* Date.py, CalSdn.py: Move to RelLib.
* src/dates/Date_*.py: Use new Date.
* src/plugins/*.py: Use new Date.
* src/GrampsDb/_*.py: Use new Date, new unserialize.
* src/*.py: Use new Date.
svn: r5875
the old Event object.
* src/RelLib/_Event.py: Remove external witnesses altogether.
* src/RelLib/_Witness.py: Make even emptier (needed for upgrade only).
* src/RelLib/__init__.py: Expose Witness (needed for upgrade only).
svn: r5595