Changing text/char fields in EMBBEventLog model to blank=True as appropriate, also adding N/A option for observation status field.

Conflicts:
	gracedb/models.py
	gracedb/urls.py
	gracedb/views.py
	manage.py
	templates/gracedb/event_detail.html

Fixed problem with SPInfo and SPPrivacy URLS. Also changed name of /events/ view to 'home-events' so the 'home' view will point to the one that is actually public.

Added public url patterns in ligoauth/middlware/auth.py. Note: This is a temporary hack to facilitate registration with InCommon.

Removed 'Alpha' from the GraceDB homepage. Also added service provider privacy and info pages, which are required for federation with InCommon.

Added N, created to EMBBEventLog. The N is for addressibility, along the lines of the EventLog object.