set up google analytics
change template loaders on production as suggested by istvan

should improve performance, templates stay in memory
eliminate need for custom.py
conditional setting of EMAIL_BACKEND
remove duplicate entries from INSTALLED_APPS
Merge branch 'style'

Conflicts:
	biostar/settings/base.py
use new analytics code
track whether we are logged in with google analytics
use a python var to determine whether user is authenticated
add search to individual post page
pad navbar buttons on small devices
provide more options in mobile mode
Merge branch 'master' into style
gravatar on sm user page
white space at top of sm nav buttons
no user location on sm user page