Move custom user controller into own file and add tests

Also moved some functional test boilerplate into a helpers module.
Add some missing __init__.py files
Move custom package controller into own module
Add a test for the custom package controller
Move custom actions into logic/action/create.py
Move copy-pasted action functions into their own module
Merge branch 'master' of github.com:ckan/ckanext-b2 into coveralls