We get no last_atime limit at all otherwise:
qutebrowser.misc.sql.SqlException: Failed to prepare query "SELECT url, title,
strftime('%Y-%m-%d', last_atime, 'unixepoch', 'localtime') FROM
CompletionHistory WHERE (url LIKE :pat escape '\' or title LIKE :pat escape '\')
AND last_atime >= ORDER BY last_atime DESC": "near "ORDER": syntax error Unable
to execute statement"
We need to tell sqlite to convert the timestamps to localtime during
formatting, otherwise it formats them as though you are in UTC.
Also fix up a few uses of mktime.
For performance, re-introduce web-history-max-items.
As the history query has now become a very specific multi-part query and
history completion was the only consumer of SqlCategory, SqlCategory is
now replaced by a HistoryCategory class.
