Trisquel studio backports

Backported the most recent versions of

• ardour
• audacity
• calf
• carla
• lmms
• patchage
• ubuntustudio-controls (as trisquelstudio-controls)
• ubuntustudio-menu (as trisquelstudio-menu)
• blender
• inkscape
• scribus

I haven't been able to backport the most recent version of kdenlive, but have backported a version that is at least newer than that in the 18.04 repo.