Correctly construct avatar URL in production.

Passing null is not OK because then ROOT_URL is ignored (because option
is passed, as null, instead of not being passed at all).
Add meta data to HTML head

Fixes bug #481.
Merge pull request #564 from nschloe/add-metadata

Add meta data to HTML head
Replaced e with event variables
Replaced e with error variables
Autofocused username when login form is rendered
Autofocused e-mail when forgot password form is rendered
Autofocused e-mail on enroll user form
Fixed search autofocus so that it doesn't take focus away from dialogs
Style.
Merge pull request #568 from peerlibrary/autofocus-username-on-login

Autofocus username when login form is rendered
Merge branch 'development' into rename-event-variables

Conflicts:
	client/accounts.coffee
Be clear about index order.
Merge pull request #567 from peerlibrary/rename-event-variables

Rename e variables into more verbose event or error
Merge branch 'development' into permissions-ui

Conflicts:
	client/collection.coffee
	client/group.coffee
	client/lib/access.coffee
	client/lib/catalog.coffee
	client/lib/controls.coffee
	client/publication.coffee

Also renamed all e variables to event (see #375)