Display a table with one row per call (instead of two lines per call),
and display the phone numbers of the people making the calls instead of
internal IDs. This should make the VTY command friendlier for end users,
especially if they have bigger networks. There is still the 'show calls'
command with all the verbose output.
Example output:
OsmoSIPcon> show calls summary
No active calls.
OsmoSIPcon> show calls summary
ID From To State
----- -------------------------------- -------------------------------- ----------
5001 101 100 PROCEEDING
OsmoSIPcon> show calls summary
ID From To State
----- -------------------------------- -------------------------------- ----------
5001 101 100 CONNECTED
Relates: OS#1680
Change-Id: I2092d58d80a34e6083f618593b92bb9e838aa906