Caller ID presentation values
-----------------------------

In some channels it is possible to set Caller ID presentation for a device. It is 
also possible to set the presentation for an active channel in the dial plan
with the setcallerpres() application.

Valid values are:

      allowed_not_screened    : Presentation Allowed, Not Screened
      allowed_passed_screen   : Presentation Allowed, Passed Screen
      allowed_failed_screen   : Presentation Allowed, Failed Screen
      allowed                 : Presentation Allowed, Network Number
      prohib_not_screened     : Presentation Prohibited, Not Screened
      prohib_passed_screen    : Presentation Prohibited, Passed Screen
      prohib_failed_screen    : Presentation Prohibited, Failed Screen
      prohib                  : Presentation Prohibited, Network Number
      unavailable             : Number Unavailable
