Sqlite >= 3.25.0 got stricter 'alter table ... rename ...' behavior
where the renaming affects all references to the table across the
database. This is at odds with our fts_view view on schema updates
due to ontology changes, as we first migrate (rename current table,
create new one, insert previous content, drop old table) all resource
tables before doing the FTS table/view updates. This causes rename
failures due to the fts_view referencing the renamed and dropped
tables.

Change the ontology update code so we delete the FTS table/view
before changing resource tables in case of FTS updates. This makes
the behavior correct both before and after the Sqlite change.

#40