Title: #390: NSS: Add option to disable memcache
I think adding to option to the man page is the only way to make sure the negative impact
of this option is properly documented and nobody can be hit by the effects of the option
by surprise (I know nobody reads man pages but that's a different story). Additionally
this way we can underline that this option should not be used in production but only for
testing or to temporarily work around an issues until it is solved.
See the full comment at https://github.com/SSSD/sssd/pull/390#issuecomment-331797883