11086 logback

See: http://trac.openmicroscopy.org.uk/ome/ticket/11086

Includes the changes for:
 * developers/logging.txt, and
 * developers/Server/Properties.txt

The file reference from the insight section does not yet exist and so the ome-docs jobs will be unstable on the URL check. We'll need to create the file before merging this PR.

The block of "up&coming docs" at the bottom might should also be removed/reviewed.

/cc @ximenesuk, @mtbc, @bpindelski