[NEXUS-6809] Add a user id search box to user list
[NEXUS-6809] Remove default filter box
[NEXUS-6809] Change grid empty text based on source/user id filter
[NEXUS-6809] Special handle for "Default" source
[NEXUS-6809] Move search box near source
Merge pull request #746 from sonatype/NEXUS-6809-user-search-box

[NEXUS-6809] Add a user id search box to user list