r860: Merge 2.1:
* Make the number of audio channels less hardcoded.
* Whitespace and formatting changes.
* Remove redundant flush() calls.
* Convert RenderFarmServerThread::start_loop() to ...::open_client().
* Add CWindowCanvas::zoom_auto() (but this seems to be unused).
* Add session_only parameter to EDL::copy_session().
* Adding of EDLSession::need_rerender().
* A subtitle hunk that was missed.
* record_speed (related to rate of the audio monitors) is now a fixed value.
* Alt arrow keys move left / right by edit.
This revision should match GIT::
4f02e843df9a19b71ce34a05fbe261e195af4387.