Updated to be more print-friendly

In order to have the tutorial printed by lulu, I had to do some changes, especially to the examples, as there was quite some overfull boxes with LaTeX. In order to fix it, I controlled that no example exceeded a limit of 80 characters a line.

I changed the title in the Makefile to "The Python GTK+ 3 Tutorial", as that describes more the contents, and as it is the title used in the tutorial itself, only the title in the Makefile was still unaltered. Oh, and I fixed the release version of the tutorial as well, as it still was static on 1.0.

A change you might consider not to include is that I eliminated the table of contents and search field, as of course, this is not needed using LaTeX. But as the main goal is HTML, unless you could make it optional for HTML as a target, it's maybe better to leave this unaltered.