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.

helpers/make-carla

+#!/bin/sh
+#
+#    Copyright (C) 2019 Mason Hock <mason@masonhock.com>
+#
+#    This program is free software; you can redistribute it and/or modify
+#    it under the terms of the GNU General Public License as published by
+#    the Free Software Foundation; either version 2 of the License, or
+#    (at your option) any later version.
+#
+#    This program is distributed in the hope that it will be useful,
+#    but WITHOUT ANY WARRANTY; without even the implied warranty of
+#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#    GNU General Public License for more details.
+#
+#    You should have received a copy of the GNU General Public License
+#    along with this program; if not, write to the Free Software
+#    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
+#
+
+VERSION=1
+EXTERNAL='deb-src http://ppa.launchpad.net/ubuntustudio-ppa/backports/ubuntu bionic main '
+REPOKEY=F596CF7036BBAA6D
+
+. ./config
+
+changelog "Backported from ppa"
+
+compile