Add support for travis-ci.

Add first try adding a travis.yml file

Fix execution of lb commands in travis file

Add a PPA with a CMAKE 2.8.11 backport

Add GCC 4.8 package since we need C++11 support

Specify g++ 4.8 some more

Getting a little desperate here

Try this again

And one more time

I don't know what to do here

Let's try to be a little more forceful

QMainWindow and QAction need QWidgets include directories

May be this will also solve Qt issues

Ok, we need Qt5.3 not 5.0.2; let's get the same as MuseScore

Forgot the Mesa/EGL dependencies