Added "active" field on asterisk.server object.
In order to access all the Asterisk servers, included the desactivated ones,
I added a view dedicated to the object asterisk.server, which is accessible
under Administration > Configuration.
- option to allow the use of phone numbers in National format,
as discussed with Albert. This option is on the definition of the server.
-> required a large change of the reformat number process
- added exact link to documentation in module description
- some clean-up