libs/ardour/SConscript.
Renamed define WITH_JACK_PORT_ENSURE_MONITOR to HAVE_etc to
be more consistant.
Added a test in libs/ardour/SConscript for jack video support and
ifdef'd the small code blocks in audioengine.cc and session_time.cc
where it was used.
git-svn-id: svn://localhost/ardour2/trunk@882 d708f5d6-7413-0410-9779-e7cbd77b26cf