Implement search by full name

[jensens]

At the moment users are only searchable by their UID, which does not make much sense.

[cekk]

@jensens what's the status of this issue? I see that there is also a branch.
I started using this plugin and this behavior could be very useful.

[jensens]

@cekk Pull Requests are accepted. At the moment I don’t have any project or funding to get this feature done.

[alecghica]

This would work eea@4a2ca4a but is not generic. I'll submit a PR when have the time to do so.