Fix up extracting ranges from previous sessions, now using ~2/8 syntax instead of ~2#8

Tidy up history retrieval APIs, and magic commands using them (%hist, %macro, %save, %edit)

Make HistoryManager configurable.

Connect storing output in database to DisplayHook.log_output

Implement optional logging of output as suggested by Robert Kern.

Tidy up store_inputs

Ability to cache commits before writing to disk, to save power.

Initial conversion of history to SQLite database.

Add option to get_history to determine whether to retrieve the current session or the entire history. Qt console on startup requests entire history.

Improve macro test, modernise magic_macro code.