[#1117] Move call_auth() into test helpers

Where other auth test modules can use it.

Also add a complete docstring.
[#1117] Check error messages in user_update auth tests
[#1117] Optimize the reset_db() test helper function

This version is faster. Code from @joetsoi
[#1117] Remove an unused import
[#1083] Add note about Apache and Nginx files
[#1083] Add note about reenabling extensions
[#1117] Add helper decorators to navl/test_validators.py
[#1083] Minor edits to package install upgrade docs
Merge branch '1083-upgrade-minor-version-instructions'
[#1139] Remove moderated option from config docs

It is no longer supported and causes lots of confusion, apart from
issues with dataset updates.
[#1152] Call check_access in member_roles_list
[#1083] Add notes about Apache and extensions to the patch release as well
[#1083] Add step about upgrading extensions
Merge branch '1083-upgrade-minor-version-instructions' of github.com:okfn/ckan into 1083-upgrade-minor-version-instructions
[#1083] Need to restart Apache as well on patch upgrades
Merge pull request #1151 from okfn/1151-auth-datastore-fix

Fix for master re datastore and auth audit
[#1117] Lots of work on the testing coding standards
Merge branch 'master' of github.com:okfn/ckan into 1117-start-new-test-suite
[#1117] PEP8
Merge remote-tracking branch 'okfn/master' into 1149-pip-requirements