Add another column for audit tables

[zaiddabaeen]

I have been browsing the documentation trying to find a way to add a new field for each audit log, but I haven't found anything.

For our use case, the audit should be "tagged" with the project ID, and users within that project should be able to see the audit log. Users of course can be added and removed to the project.

At this time, audit logs seem to be owned by a user, but for our use case, it is owned by a project, and we still need to know who was the user who performed the action.

If it does not exist yet, then providing a way for devs to extend the audit log entity (like how FOSBundle does it with FOSUser) can do the job.

Thanks!

[josipjelic]

+1

[Lehren]

+1

[DamienHarper]

see #61