Fixes spec for admin users visiting unpublished pages.
Store all open dialogs in a collection for further reference. Refs #466

- Alchemy.currentDialog is now a function that returns the last dialog instantiated.
- Alchemy.closeCurrentDialog() now closes the last dialog instantiated.
Wait 'til the upload dialog is closed before refreshing the archive window. Closes #466
Styles the create language tree form. Closes #470
Fixes indention of haml element editor partial. Closes #472
Ensures that the redirect gets called even if no dialog is open. Closes #473
Removes duplicate please wait overlay call while saving page order.
Explicitly set the language_code after creating a page. Closes #474
Adds global help window accessible via ? key.

This help window only shows keyboard shortcuts at the moment.
Do not raise errors for element definitions having nil as contents value.
Fixes element partial generator for elements only having available contents.
Make url field for internal link editable.

So one could add a anchor manually.
Fixes add content button.
Fixes dynamic cell tabs creation.
Do not show help window if ? key is pressed inside of text field or text area.
Merge remote branch 'upstream/master'

Conflicts:
	app/assets/javascripts/alchemy/alchemy.hotkeys.js.coffee
	app/assets/javascripts/alchemy/alchemy.translations.js.coffee