Add script for linting application with Pylint

Also update the documentation with instructions for using the script.
Remove useless pylint config file

The Pylint config file is useless for several reasons:

1. It is unused by `lint.py`.
2. It does not set any especially useful or interesting options. In fact, it
   sets options in a way that are actively harmful. For example: disabling all
   warnings!
3. Inline Pylint directives (e.g. `pylint: disable=W0262`) are likely to be
   sufficient for customizing the behaviour of Pylint.