Merge pull request #18 from sgillies/master

Clarify representation of unlocated features.
Merge pull request #19 from sgillies/master

Specify that Feature.id SHOULD be a string or number.
Merge ../sg-draft-geojson
Pluralize section headers in appendix.

Reads well and works better with xml2rfc.
Update the date to today.
Changes RFC 4627 refs to 7159.

Closes #21.
Bump version and set date.

Beware the Ides of March!
Add draft registration fields.
Add security considerations.
Correct email, refer to RFC7159.
Reference KML in two places.
Add suggested comma. Closes #25.
Add security and IANA considerations.

media type is application/vnd.geo+json.
Bump version to -03.
Fix typo mentioned in #25.
Incorporate IANA comments.
Update sections 5-7 after completed IANA registration.
Empty coordinates guidance for processors.

Closes #23.
Set date to 2014-05-21.
Change in wording suggested in #30