Changes dynamic and lexical schemas to be stored internally by the URI as a string

[kjeldahl]

Fixes #188

[kjeldahl]

Suggested change

	@resources[type][namespace_uri.to_s] = schema
	fail "Schema already registered as #{type} under #{namespace_uri}" if @resources[type][namespace_uri.to_s]
	@resources[type][namespace_uri.to_s] = schema

Check whether the URI is already used for possibly another schema. It makes a couple of tests fail though.

[davishmcclurg]

Sorry for the delay—thanks for opening this!

[davishmcclurg]

Let's just call these uri—I don't know if "namespace" is the right terminology here.

[davishmcclurg]

I think instead of wrapping both of these in a single object, we should pull them into separate objects. Something like:

def resources
  @resources ||= { :lexical => Resources.new, :dynamic => Resources.new }
end

Or even separate lexical_resources and dynamic_resources methods.

And then on Resources you just have to define the Hash methods that we're using (#[], #[]=, #fetch, and #key?).