VERSIONS.txt is years out of date and should be moved to Sphinx

described in http://trac.openmicroscopy.org.uk/ome/ticket/11528
remove ancient psql-replace-regexp elisp
SQL upgrade from 4.4.8 to 5.0beta2
add post-DEV_6 SQL from PR #1645
separate new function into separate script for OMERO5.0__0
merge in an additional change from 909ffb3e
Merge pull request #1691 from mtbc/db-upgrade-11516

fix #11516: add upgrade scripts from 4.4 to 5.0