Add support for site-wide announcements, and simple messaging.

Announcements are for more sustained notifications to users,
messages are transient notifications that disappear on a page reload.
Add django-admin-tools and admin page customization
Merge branch 'master' into messages

Conflicts:
	project/settings.py
	rvbd-portal/rvbd_portal/apps/datasource/admin.py
Clean data values of numpy types because json can't always stringify them
Clean up resolutions / durations a bit, support ms-resolution for shark
Fix problems with QoS Criteria processing and hidden criteria fields
Enhance admin site, lockdown some views to admin-user only
Cleanup announcement styles
Merge branch 'messages'
Remove debug logging and pdb statement
Only save preferences for admin user, avoids conflicts if new users added and db reset
Add optional ldap backend authentication with settings defined in settings_local.py

- bootstrap.py now includes a base template 'settings_local.py' file where LDAP
settings can be configured