Updates to Ubuntu package building process

Marble can't be static, so instead we build a shared library but give it a
different name so it can be installed in parallel with the "real"
libmarblewidget.so.

Also make sure that the correct libusb is installed so that Atomics Aquatics
dive computers are supported.

Fixes #782

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>