Suggestion: db_save_on_rebuild

[NotNull]

Suggestion to make db_save_on_rebuild=1 the default instead of =0.

There were a couple of issues reported by people that lost their indexing results because they weren't saved.
Especially with property- and context indexing rebuilding can take a long time.
(or is there a setting to save after initial indexing that I'm not aware of?)

[therube]

(I'll note that while -save-db does update Everything.db, to disk, it does not first save the existing to .backup.db.
.backup.db is left unchanged [till you Quit].)