In the latest released version of dateutil, there's a bug whereby a TypeError
can be raised whilst parsing a date. This is because it calls a method which
it expects to return 2 arguments, however it can return 1 depending upon the
input, which results in a TypeError: ArgType not iterable exception. Since
this is equivalent to a failed parse anyway, we can treat it the same as a
ValueError.
Migrate changes to include updating single elements of ListFields as
well as MapFields by adding the same changes to BaseList. This is
done by ensuring all BaseDicts and BaseLists have the correct name
from the base of the nearest (Embedded)Document, then marking changes
with their key or index when they are changed.
Tests also all fixed up.
Damien Churchill