This strategy relies on the history being exactly in the order in which
commands have been entered. Therefore, options like suppressing
duplicates or expiring duplicates first will lead to unexpected
suggestions.
According to a few tests, the `fc` builtin appears to be quite a bit
faster than searching through the `$history` associative array when
dealing with large history files (500K+).
$historyarray tofcbuiltin for better performance with large HISTFILEs (#164)extended_globis set (#168)