Fixes#171Fixes#199Fixes#118Fixes#178
Added: tests for building documentation and example code in documentation
Added: docstrings for common used functions and classes
Removed: old documentation
* Removing all the "#!/usr/bin/env python" lines, they do not need for python3, solving issue number: #19.
* Restored all the shebangs in the tools and tests folders (because they are real executables) but used "#!/usr/bin/env python" instead of "#!/usr/bin/python" as this blog points out: https://www.peterbe.com/plog/importance-of-env
Removed also the shebang from pdfminer/psparser.py file.
Pieter Marsman
Igor Moura
Martin Hasoň
Venelin Stoykov
Antonio Ercole De Luca
orangain
Cathal Garvey