Add blessings
Begin work on a new coloured shell output module

Based on Blessings to make it much clearer how it works.

It's clear that the existing represented() methods are not really
sufficient for writing the coloured output (unless you like reprocessing
strings).
Refactor after/before callback registries to use factory

This has the advantage that the decorators actually exist and can be
detected with pylint.
Some more coloured output
Show stderr in red, add counter for examples, unicode workaround
Merge branch 'new-color-outputter' into new-parser