Note the old OPTIONS file in src/ is no longer used.  Now you must use the
configure script with appropriate options to enable/disable features.  The
check for crypt and some other things should now be automatic, and you
shouldn't have to worry about it but it can still be disabled via the script
if you so desire.

Some of the file formats may have changed, so be prepared to do a bit of work,
always make a backup first!