etcdenvironment: order map keys consistently
Merge pull request #155 from jonboulle/etcd

etcdenvironment: order map keys consistently
Merge pull request #154 from crawford/metadata

metadata-service: Add new datasource to download from metadata service
cloudinit: retrieve IPv4 addresses from metadata

This uses the new MetadataService implementation to retrieve values for
$private_ipv4 and $public_ipv4 substitutions, instead of using
environment variables.
initialize/env: fall back to COREOS_*_IPV4 env variables
initialize/env: add notes about tests
Merge pull request #158 from jonboulle/nettttt

cloudinit: retrieve IPv4 addresses from metadata
metadata: add links to metadata source information
Merge pull request #161 from jonboulle/doc

metadata: add links to metadata source information
cloudconfig: Process metadata before userdata

This gives the options in userdata a higher precedence over metadata.
metadataService: Check both ec2 and openstack urls more explicitly

Remove the root url parameter for -from-metadata-service since this
is a guarenteed value. Additionally, check for both ec2 and openstack
urls for the metadata and userdata. Fix a bug with the -from-url
option and a panic on an empty response.
metadata: Add version numbers to metadata information