Pyndl

* removes duplicate outcomes, when remove_duplicates=True was given in preprocess.py (thanks to Christian Adam kuchenrolle for spotting and fixing the problem)

- fixes bug in pyndl.ndl which did not run the events in order
- fixes pylint errors and improves code quality
- excludes files from zip and tar.gz archives

* fixes memory leak in pyndl.ndl.ndl
* fixes problem with pyndl.sysinfo()
* enhances pyndl.ndl.ndl by allowing to specify the temporary directory (thanks to Christian Adam)

fixes `setup.py` to make package pip installable.

Gets rid of older code and removes some old API. Improves documentation a lot. In more detail:

* removes incomplete code for Kalman filtering
* removes command line interface for corpus.py
* heavily improves documentation
* adds citation information
* cleanups of configuration files
* does not depend on matplotlib and docopt anymore

New function `pyndl.sysinfo()` is added to provide details in case of bug reports.