Fixed handling of missing album release dates.
Updated old classes on sign in button.
Reorganized blocks in user's profile to fix overlapping in case when email address is too long.
Added link to a page with documentation for developers.
Merge branch 'cb-22' into stage1

Conflicts:
	client/critiquebrainz/templates/album.html
Merge branch 'signin-button-fix' into stage1
Merge branch 'profile-design-fix' into stage1
Merge branch 'dev-page-link' into stage1