Hi Schlamar, I've been hacking on this program a lot, can we discuss merging?

I have made a lot of changes:

- renamed the pip package to `latexmake`, mainly so I could put my changes on pypi. If you are interested in merging I should probably change it back to `latexmk.py`. 
- added a number of features, the major one being watching files for changes. Another one is notifications of successful builds and errors through Gnome desktop notifications. 
- I used some python3-isms so the code currently is python3 only. Since this is a stand alone program and not a library I don't consider that a big problem, but it would be possible to make the code python2 compatible again. 
- I've changed the license to GPLv3+, since I prefer my code to be copylefted. 

You may not agree with all the changes I have made, so this pull request is mostly intended to discuss if you are interested in merging and what. 

My code has an optional dependency on the python inotify package. You can find a working version at http://bitbucket.org/JanKanis/python-inotify.