Disable databases & overlays (experimental)

Disable databases & overlays (experimental)

Do not use. backend/overlay code needs to be fixed accordingly.
In particular, code which currently frees configuration in _db_close()
must be changed to free only in _db_destroy().

After restructuring, it must be possible to call _db_close()/_db_open()
multiple times in succession without requiring _db_config() in between.