Force `strictProperties` on resources to `true`
Mondate particular formats for resource `properties`

Either a reference, a schema defining an array that specifies `items` as
a reference, or a schema of subreferences.
Only allow parameter names with lowercase letters and underscores
Force hrefs to match expected URL formats
Re-organize aphabetically
Property double-backslash escape regex
Allow an empty `identity` schema for intermediary resources
Merge pull request #115 from interagent/brandur-meta-improvemnts

Meta-schema improvements