Add data migration fix for a59b3163

This ensures all NoneTypes are converted to False prior to running
the schema migration.

Note, this requires a rollback to 0005 prior to running these
migrations.
Add System.failed_list_transition method

This returns True if the last transition had failed. The primary use
case is for reporting current system-level status.
Overhaul of interface for viewing systems

This is now a single page with all systems listed on the right. Each
one can be clicked on to load and view details about the system.

There is much more work needed to handle scaling up to many systems such
as lazily loading systems, explicit search, filtering by name or content
type, etc.