Add missing createOrUpdate method to ECA.

As the entityManager supports this, so should the entityCursorAdapter,
without having to grab the manager directly.
ECA crud methods now work with EntityTypes.

This is very handy when you wish to delete or create / update an EntityType,
but don't have the reference to which row it originated from.

An example use case is when one wishes to delete a row by clicking on some nested
imageView contained within. That imageViews onClick listener (bound in the
EntityCursorAdapters bindView method) will not receove a reference to which row
itself is contained in, but will have a reference to the current EntityType being
processed (which is provided through the bindView parameters).