Errata around NameID Mgmt

["Scott Cantor" <cantor.2@osu.edu>]

All language cleanup in light of repeated questions. I also could easily be
stepping on existing errata, but I'm trying not to. We need a red line
version.

The goal here is to clarify these fundmantal issues:

- NameIDMgmt applies to most of the formats
- NameIDMgmt affects only a given identifier for a principal, not every
possible identifier that might exist for a principal (this is intended as a
simplifcation)

If that's not the intent of the TC, let me know. It was my intent. I could
be misremembering earlier arguments and their outcomes back in the
AllowCreate days, but I don't think so.

-- Scott

Profiles, line 1319, change "some form of persistent identifier" to "some
form of long-term identifier (including but not limited to identifiers with
the Format urn....persistent)"

Profiles, line 1323, change "about the principal" to "using that
identifier".

Core, lines 3337-3339, I'm inclined to say that text should be struck.

Core, line 2477, change "it will no longer issue assertions to the SP about
the principal" to "it will no longer issue assertions to the SP using that
identifier". This does step on an errata, but is a separate change from it.

Core, line 2483, change "regarding this principal" to "using the primary
identifier".

Core, line 2487-8, change "regarding this principal" to "in any case where
the identifier being changed would have been used".