app_dial: Add dial time for progress/ringing.

Add a timeout option to control the amount of time
to wait if no early media is received before giving
up. This allows aborting early if the destination
is not being responsive.

Resolves: #588

UserNote: The timeout argument to Dial now allows
specifying the maximum amount of time to dial if
early media is not received.

(cherry picked from commit e4adc962ca7b733b222cf2069f70188fb74f1583)