Added discussions and annotations, references, identifiers, and formatting

Corrected typos.
Fleshed out Security Considerations.
Wrote Diagnostic Notation.
Added new identifiers to headers.
Changed to "object identifiers" more consistently.
Added multi-valued street field.
Added tocdepth="1" ([tocdepth, 1]) processing instruction.
Added PKILCAKE reference.
Updated Makefile to change <spanx style="verb"> to <spanx style="vbare">
in the Examples section only.