Update product page links & 4.4 docs link messages
Fixing feature link in sidebar menu
Merge pull request #664 from hflynn/release_updates

Update 5 docs for release changes
Users & sysadmins update text
Emphasize omero_prefix over omero_home
Add new page for omero_home recommendations
Cross-reference the new omero_home page
clarifying 'OMERO_PREFIX' in install doc
Style & proofing edits & clarifying OMERO_PREFIX
Fix rst role name typo
merge dev_5_0 -D org -I include -E exclude: PR 666 (what's new for 5.0 updates)
merge dev_5_0 -D org -I include -E exclude: PR 667 (Add details for omero_home usage)