Use a moved_entities table to record external entities moved to the system source
Instead of using a negative eid in the entities table, move the record
to a new table so we don't have an interval with a missing eid in
entities.
Related to #4846892
include *.py
include */*.py
recursive-include data *.gif *.png *.ico *.css *.js
recursive-include i18n *.po
recursive-include wdoc *