Add docstrings for sphinx.
Add docstrings for sphinx.

geotagx/pybossa,inteligencia-coletiva-lsd/pybossa,OpenNewsLabs/pybossa,stefanhahmann/pybossa,jean/pybossa,Scifabric/pybossa,harihpr/tweetclickers,stefanhahmann/pybossa,PyBossa/pybossa,jean/pybossa,inteligencia-coletiva-lsd/pybossa,Scifabric/pybossa,harihpr/tweetclickers,geotagx/pybossa,PyBossa/pybossa,OpenNewsLabs/pybossa