Ok.. There are two new options, -u and -s. -s requests that only the secure
database be touched. I've also changed it so that the cache size is bumped
for larger password files. Maybe that could become configurable some day -
for now there are two preprocessor symbols defined at the top of the file.

For performance to be decent in more cases the database format needs to be
changed. Unfortunatley there are some compatiblity issues there.

Andrew