Supressed updates for identifications added as part of taxon changes.
Made all taxon changes create updates for affected users.
Put a 5 min cache on home page observations for everyone.
Removed seriously slow select clause in one of Observation's scopes.
Bugfix: js bug on dashboard was preventing subscription links from working for new users.
Apparently that distinct was important. Need to find a better way to do that.
Merge branch 'master' into i18n

Conflicts:
	app/views/welcome/index.html.erb
Translations for home.
Not sure why this didn't merge in.