Ticket #48896 - Default Setting for passwordMinTokenLength does not work
Description: passwordMinTokenLength is supposed to be used for the
length of comparison between the substring of obvious strings and
a new password. But it was not used to generate substrings. This
patch implements it.
Also, old_pw was leaked in modify if password history was not enabled.
https://fedorahosted.org/389/ticket/48896
Reviewed by mreynolds@redhat.com (Thank you, Mark!)