This patch contains:
- updated libcrypt, which includes new api: crypt_makesalt
- revised/rewritten crypt(3) manpage, detailing the uses of Modular Crypt Formats, and new crypt_makesalt api
- refactored pam_unix to use crypt_makesalt, instead of its own format
- refactored pw to support Modular Crypt Formats in login.conf
These things combined allow using Modular Crypt Formats in login.conf to be recognized by the system. Ultimately, this will allow selecting any supported crypt algorithm with whatever parameters that it supports, e.g. $2b$11$.
Contains modifications from the patch included in https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=182518, rebased on -CURRENT.