Suggested mailing list note update (rebased onto develop)



This is the same as gh-679 but rebased onto develop.

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Updated note text to be propagated to http://www.openmicroscopy.org/site/community/mailing-lists and http://www.openmicroscopy.org/site/contact-info
@joshmoore @qidane

(this will need rebasing & releasing on the 4.4 docs as well as the OMERO 5.0 docs)