Merge pull request
#2311 from minrk/trait_change...
Merge pull request
#2311 from minrk/trait_change
always perform requested trait assignments
Some assignments do not change value, but do change the object,
and these should not be ignored.
For instance, container objects are currently impossible to assign
if they evaluate as equal, even if their types don't match
(e.g. assigning an empty defaultdict to a Dict trait, which prompted this PR).