New Features
* Add ``datalite.mass_actions.copy_many`` which allows one to save numerous objects to *another* database
* Functions of ``datalite.mass_actions`` module now issue a ``ResourceWarning`` when memory safety options are toggled off.
Changes
* Rename ``datalite.mass_actions.create_many_entries`` to ``datalite.mass_actions.create_many``
* Exception ``MalformedContainerError`` split to two new exceptions, ``HeterogeneousCollectionError`` when given container isn't heterogeneous and a ``ValueError`` when an empty list is passed.
Altered Behaviour
* Function ``datalite.mass_actions.is_homogenous`` depacrated in favour of private function ``datalite.mass_actions._check_homogeniety``, which throws the affromentioned ``HeterogeneousCollectionError`` if the passed container is not homogenous.
* Behaviour of homogeneity checks is altered, now a list (or a tuple) is deemed homogeneous even if one of the later elements of the list is a superclass of the class of the first element of the list.