Create Ubuntu PPA including our dependencies

When we migrated to GStreamer 1.0 we had to patch some regressions which had made their way into GStreamer since 0.10.  These patches have been submitted upstream but not yet made their way into a stable release of GStreamer, let alone the major distros.  This makes it very difficult for our users to install and deploy stb-tester.  This is an attempt at simplifying this process by providing appropriately patched versions of our dependencies in an Ubuntu PPA.

This also includes a dkms package to allow distributing a patched version of the uvcvideo driver.  This is required for Smart TV support with the Logitech C920 driver.

The code isn't beautiful but it lives in extra/ and is a tools for maintainers rather than users or developers.

The PPA can be found at https://launchpad.net/~willmanley/+archive/stb-tester/ .

[gst-plugins-good doesn't currently build correctly on Ubuntu's servers](https://answers.launchpad.net/launchpad/+question/246044) so can be [provided separately for now](http://williammanley.net/ubuntu/saucy/gst-plugins-good1.0/).