Everything has been rewritten to have a correct naming standard.

While rewriting, network.py has been set as a library of functions, not
object-oriented. The reason for this is that there is no need for it to
store or encapsulate any data. Its use cases are more functional.

Also, it makes no sense that user interface has to use NetController to get
information only related to the network status, and not to the controls
themselves. This will be the responsibility of the library network.
Makefile: Added options `install`, `uninstall` and `clean`.
tests: Sometimes, nosetests doesn't discover the tests by using the `-w`
option. This commit is a work-around to get it working at all times.
However, this should need further investigation.
tests: The renaming in the commit a9cfc44c09e00682fd7941a9913b44441793c3f5
broke the test. It has been fixed.
Makefile: Added `force` option when installing the main executable
(symbolic link). This prevents having an error when doing two consecutive
`make install`.