Incorporate method names from RFC 344

Adds a convention for types appearing in method names.
Incorporate RFC 356

Adds a convention for disallowing module name prefixes in the exports of
that module.
Incorporate getter/setter names from RFC 344
Incorporate iterator type names from RFC 344
Reference RFC 199 for iterator method names
Reference RFC 199 for ownership variants, mention into_iter
Clarify conversion guideline citation