formatting improvements for group table
fixed some message bundle references in import service
eliminated CredentialBean
credential table improvements
eliminated ImportService.getGroupMemberships

Now the interface provides only a flag property indicating whether the
user is a member of groups in addition to "self".
import service now creates owner group on the fly
updated user stories
delete control is groups view now disabled for in-use groups
moved User and GroupAccessException to base service package
completed Owner Auto-Create Feedback story
fixed broken unit test