This change is to support extra properties in project and user.
To show an extra property in project/user table, you can customize.
The explanation of the method to add an extra property is added
by this patch.
In addition, when you do a create or update user, you can specify a
value of extra property by setting in local_settings.py
Change-Id: Ifee491f2a55d9207fe5da70136f749e1fc4bab82
Implements: blueprint support-extra-prop-for-project-and-user
ab11eef92a