GUI-771: Fix snapshots landing page failure on AWS when a snapshot's volume has been deleted

Fixes https://eucalyptus.atlassian.net/browse/GUI-771

Using `conn.get_all_volumes(volume_ids=volume_ids)` fails on AWS if any of the volumes in the volume_ids set have been deleted.  Switching to filters fixes the issue on AWS and works for Eucalyptus as well.

Also includes style fixes for the volume detail page--deleting/deleted states weren't displayed properly, and the disabled button state displayed as green across the site.