Again, a set of improvements

Again a set of improvements for Headphones. 

* e69cf39 + 21b3d99 increase logging for Last.FM responses, so we could fix #1877.
* 34b9480 removes the unused pyItunes module. It was imported somewhere only once, but not used.
* f4b1353 fixes #1864

The rest are just improvements to logging and proper exception catching. 
* I explicitly [catch from](http://stackoverflow.com/a/730778/1423623) Exception class where applicable, or be more specific what to catch. 
* Use `with open(..) as f` instead of `f = open(..)`. The first closes `f`, even in case of exceptions, and does not rely on the the interpreter to close files.
* Code formatting things

And again, it's barely tested :-)