Merge branch 'master' into nigeria

Conflicts:
	mzalendo/core/static/css/nigeria.css
	mzalendo/core/templates/core/person_detail.html
	mzalendo/settings.py
Correct colours on paginated positions
bump static version number to force browser reload
Drop 'National Assembly' from menu
Update homepage wording. Closes #589
Start script that targets new PopIt API
Skip hansard tests unless a host has been set to run PDF to HTML conversion on
Add tests for current (buggy) display_dates implementation
Correctly display dates for positions that have an end date - closes #597
Fix wording for the rest of the possibilities
switch django_date_times to be the new version
Add validation tests for position end_dates
Adapt the display dates to to create 'past' related messages
Adapt the position sorting to cope with past dates.
Use django-date-extensions from pypi
Use mirrors when fetching pypi parkages (should be much faster)
Correct django package name
Merge branch 'nigeria'

Conflicts:
	mzalendo/core/templates/core/person_detail.html
	mzalendo/settings.py
Server pip does not have '--use-mirrors'
Correct a misspelling of 'spoken'