* sync schema.sql with running schema
* remove incognito field from history table. also don't add empty FeState vars
* history updates, add festate, durationms, exitcode, status, and tags into history table
* update screen/session delete, and clear to no longer purge history items. move deleted screens/sessions into a tombstone table.
* update schema
* fix alias -> fn
* quiet the security warning about an unchecked byte conversion. no real security issue here, but add a range check for good measure.