Thanks to Adrian Bunk for spotting this.

Fixes lintian appstream-metadata-in-legacy-location.

Marvosym font files are still shipped with the test data, so no further
changes are needed.

This makes the text-font-symbol test fail at build time, which is yet to
be investigated but non-fatal given a nomber of other tests fail as well
and the test suite is currently run but not depended on.

The respective lintian override is kept in place until the package is
actually gone.

Because https://bugs.debian.org/798900 is now closed in lintian

Options that are now default are dropped

As recent debhelpers already work around qmake's stripping of binaries
by passing QMAKE_STRIP=:, qmake can now be invoked with `CONFIG=-debug`
(as upstream recommends it for release versions.

upstream release 2015.03-2 without unattributed parts

The erroneous specification of the build conflict against GLES (which,
by how QT's OpenGL packags are built, makes OpenSCAD unbuildable on ARM
these days) made the builders try to build OpenSCAD on platforms where
it could not succeed.

See https://bugs.debian.org/797816