Add docstrings and unittests for colorizer.py.

New changesetee0f927bd8dba805a04963dbec1ad49fe830b842 by Terry Jan Reedy (Cheryl Sabella) in branch 'master':bpo-35689: IDLE: Add docstrings and unittests for colorizer.py (GH-11472)https://github.com/python/cpython/commit/ee0f927bd8dba805a04963dbec1ad49fe830b842

Thank you for writing this.  I was NOT looking forward to tackling tests for this module.I have thought about merging delegator and colorizer into one module, possibly with percolator included, and adding a module docstring that explains how they work together.  This would still be only a few hundred lines.  (And multiple htests in one file are not an issue.)  What do you think?There is a suggestion in percolater that Percolater could subclass Delegator.  I have not seriously looked at that idea yet.In the first code comment I mentioned a follow-up code change.  Did you have anything in mind to work on or did you pick this for the fun and challenge?

New changeset99e9c36b29a194d59ee4b0d8b82a72f5b0d409dd by Miss Islington (bot) in branch '3.7':bpo-35689: IDLE: Add docstrings and unittests for colorizer.py (GH-11472)https://github.com/python/cpython/commit/99e9c36b29a194d59ee4b0d8b82a72f5b0d409dd

> I have thought about merging delegator and colorizer into one module, possibly with percolator included, and adding a module docstring that explains how they work together.  This would still be only a few hundred lines.  (And multiple htests in one file are not an issue.)  What do you think?undo also uses delegator.Delegator as a base class.  It might be odd for it to come from colorizer.delegator.  I like the idea of explaining how they all work together though.> I have not seriously looked at that idea yet.Neither have I.  There are other things I'd like to get done (in this and other modules) before thinking about that one though.> In the first code comment I mentioned a follow-up code change.OK, I'll create an issue for that.  I *really* want to rename the `any` function too.  It took a lot of willpower to not touch it when writing the tests.  :-)> Did you have anything in mind to work on or did you pick this for the fun and challenge?:-)  Since the goal is to add tests for everything, I figured I'd tackle this one.  But, I specifically thought it would be good to have tests in place in order to work on#29287.