Fixed grouping issues by devices

Some dodgy sorting was screwing up how the issues were being grouped.
This is now fixed.
Removed group by devices

Grouping by device is too much of a hassle, as there is no uniquely
human readable field for each device so I'm removing it.
Removing cinema/devices sorting entirely

We were seeing a strange SQL bug when sorting by cinema or device and so
for this release we're just going to comment this stuff out.
Merge pull request #73 from dannybutler/group_by_devices_fix

Fixed grouping issues by devices