We're not yet saving the hex colors as that will break in older patches.
But we do print out warning messages in this interim period and will
save the hex colors at a later date. Once that change is made, all the
interim versions will be able to read the new format

This is an initial attempt at a regression testing framework.

Initially it has some regression tests that come from the work on
improvements to the msg box.

The framework allows the tests themselves to remain extremely simple. They
just need to send a number and potential error message to the outlet.

However, they do need to be added in the main patch. This is because we
will need to run some tests in a certain order. We could number the test
filenames but that's less easy to change later.