Improve home page
Improve base page + cleanup
Improve other pages + cleanup
Reinstate conference.html that I should not have touched. Include images.
Merge branch 'develop2' into develop

Conflicts:
	appengine_app/static/images/speakers/pieter-jan-vandormael.jpg
	appengine_app/templates/base.html~
	appengine_app/templates/blocks/footer.html~
	appengine_app/templates/pages/agenda.html
	appengine_app/templates/pages/speakers.html