The "warnings" branch has been merged into "devel" and "fstrings"

[Edward K. Ream]

This merger continues the transition from python 2 to python 3.  It also closes #1454:

Many warnings, both from python -Wd and pylint are gone.

The highlight is the new g.import_module.  This is a thin wrapper around importlib.import_module. It's much easier to use than the old code base.

Many other changes were made.

Please report any problems immediately.

Edward