Migrate sparkle to sqlite

The first working commit of sparkle on sqlite.

Commands broken by this release: addban, allpastnames, catfact,
listbans, mostnames, mypast24hours, mypastweek, mystats, namechange,
past24hours, pastnames, pastweek, pilgrim, stats, unban. Holiday tables
also don't work yet. (These should all be fixed in future commits)

Additionally, there isn't a migration script written yet to convert
existing DBs to the new format.