If no control port is given to add/forgetDestination, ccrtp will assume you
want rtp_port + 1. Since this is the behaviour we rely on for addDestination,
we should use the same convention for forgetDestination, instead of
explicitly saying remote_port_ + 1.

They might be different.

A call can send one codec and receive another.

This will allow assymetric audio codec use (i.e. send with one, receive
with another).

move transportRate to audioRtpSession instead of audioSymmetricRtpSession

They must be sent repeatedly and eventually with an end bit set.
Fixes regression from commit 9a8bc388

99 % of these are just whitespace changes. Some unnecessary includes
removed as well

gnome-client still has leftover icon that crashes when clicked on.