Hilariously, simply removing the ambiguity test for flaglike values (almost) Just Works.
Hilariously, simply removing the ambiguity test for flaglike values (almost) Just Works.

Makes the lack of doing it this way originally all the more perplexing.

Includes one extra debug log message I needed while figuring this out,
which feels overlooked from previous.

Fixes #516

pyinvoke/invoke,pyinvoke/invoke