Add missing Python 3 classifier.
Mark next release as 1.5.5.
Make UserList pass the ``is_collection()`` test.
Remove a work-of-god behavior.
Test xoutil for Python 3.4.

Results:  There was a change in OrderedDict __reduce__ behaviour.
Nothing else fails.  TODO: Either backport from Python 3.4 or fix the
test.
Remove PyPy "official" support.
Fix the failing test for Python 3.4 OrderedDict.

However, a throughout review is in order.
Backport ChainMap from Python 3.4.
Improve support for PEP 3115 - new metaclasses.
Include next release changelog.
Warn when using __prepare__ in Python 2.7.
Ensure all collections.abc are importable.
Note that ChainMap is backported from py34.
Add MappingProxyType.
Add SimpleNamespace.
Update changelog with MappingProxyType and SimpleNamespace.
Add DynamicClassAttribute.
Change some invalid arguments in CLI.
Create a new module `security` for creating passwords.
Merge branch 'develop' of /media/med/merchise-git/xoutil into develop