Add poltergeist

* Add poltergeist for running tests that need JS
* Move test helpers into their own file
Add failing spec
Merge pull request #25 from kete/rr/nokogiri_fix

remove errors Nokogiri errors
Merge branch 'kete2' into ek-audio-upload
Get basic audio upload working
Stop tests failing because of failing to find indicator gif.

Globally replace '/images/indicator.gif' with #{image_path('indicator.gif')}
Add spec to show that video upload works.
Merge pull request #26 from kete/ek-poltergeist

Add poltergeist
Merge remote-tracking branch 'origin/ek-audio-upload' into kete2
Merge pull request #28 from kete/ek-video-upload

Video upload
Merge branch 'kete2' into rr/add-item-topic-fixing

Conflicts:
	app/views/account/_avatar_updater.html.haml
	app/views/account/show.html.haml
	app/views/baskets/new.html.haml
	app/views/comments/_form.html.haml
	app/views/configure/_link_to_site.html.haml
	app/views/configure/index.html.haml
	app/views/importers/_extended_field_selection.html.haml
	app/views/importers/create.html.haml
	app/views/search/_form.html.haml
	app/views/search/rebuild_zoom_index.html.haml
	app/views/search/related_form.html.haml
	app/views/topics/_tags_div.html.haml