Standard -4.3.1 Remove PPID from scope and add it to the req object

[Nat Sakimura]

PPID is not a scope. Thus, remove.

Add it back to the request object.

[Nat Sakimura]

Make it a section like OAuth.

[John Bradley]

fixes #216 added "pair_wise" and "public" to list of identifier types

→ 94237b74522e

[John Bradley]

fixes #216 added user_id_type

→ ddf1c60c997c

[John Bradley]

fixes #216 remove PPID scope

→ fb41eaf4671d

[Casper Biering]

The example in Discovery 5.2 need to be updated to "pair_wise" from "public".

Shouldn't "pair_wise" be called "pairwise"?

[John Bradley]

fixes #216 changed pair_wise to pairwise and fixed up examples in sec 5.2

→ d7192aca538c