Suggest using OMERO.ij instead of the "Download from OMERO" plugin
Update omero_client.jar to 4.4.8p1

This allows the "Download from OMERO" plugin to work with 4.4.x servers.

Fixes #10770.
Clarify OMERO plugin deprecation
Merge pull request #698 from melissalinkert/ticket-10770

Fix "Download from OMERO" plugin for 4.4.x