Added a common parent class for User and Contact to reuse code
Merge branch 'master' into cperello/samba-contacts-distribution-lists

Conflicts:
	main/samba/ChangeLog
Removed unused 'use' clauses
Improvements in the object creation for user and contact objects
Initial support for Contacts in Users module
Merge branch 'master' into cperello/samba-contacts-distribution-lists

Conflicts:
	main/samba/ChangeLog
	main/users/ChangeLog
Changed the way we extend the OrganizationalPerson to follow the same implementation as the users module
Moved back _checkAccountName validation into samba's user implementation given that it only affects user names
Updated the User sync between Samba and Zentyal with the new fields added
Fixed the way we track the LDAP core attributes. Fixed the method to query the user groups
Fixed typos
Initial implementation of Contacts handling
Return the righ ID so we are able to check whether the contact exists
Fixed a bug when you remove a row on 100% volatile DataTable with 'ids' method overriden
Added working tests
Added Contact edition support
Updates to support Contact edition
Updated code to sync Samba and Zentyal contacts
Implemented provision from OpenLDAP to Samba for contacts
Split Zentyal specific LDAP schema into its own file and prepared to use the new distributiongroup feature