Better keysalt docs

Add a new section to kdc_conf.rst to describe keysalt lists, and
update other documentation to better distinguish enctype lists from
keysalt lists.

(cherry picked from commit 23a75649277afc24a9dfea199689e18129fa390c)

ticket: 7608
version_fixed: 1.12
status: resolved
Update man pages
make depend
Updates for krb5-1.12
Update for krb5-1.12-postrelease