Add a better mechanism to detect Entity changes

Implement and use a better mechanism to detect changes of attributes of
the Entity objects by using a private variable which keeps track of the
changed Entity attributes ("properties") via the "set" method.

The "insert" and "update" method of the Repository now calls the method
"getModifiedKeys" of the Entity class to get a list of properties which
have been changed and builds the database query accordingly.

This makes the use of "FALSE" as default value for the Entity attributes
obsolete, so they have been set to the initial PHP default ("NULL").

0 files changed, 0 insertions, 0 deletions