Add support for emitting raml markup

This is actually not yet ready for a pull request, but wanted to get feedback on the approach so far.

What I like about this changeset is that it works, I can generate workable RAML from wsdoc and use the results in RAML presentation tools (API Console, raml2html, etc.).  It uses Jackson jsonSchema module to produce json-schema describing request and response DTO's, and keys on the Jackson @JsonPropertyDescription annotation for description on each property.

There are some downsides, though:

(1) The combination of annotations processing and reflection based processing is an odd mix.  Using the jsonSchema module adds a dependency that the class be pre-compiled and on the processor's classpath.

(2) The jsonSchema module required a patch to make it process the @JsonPropertyDescription annotation correctly, so being able to take advantage of that depends on a pull request I submitted for that.

(3) The jsonSchema module seems emotionally unequipped to deal with recursive DTO's.  I think I can fix that, but then there's another dependency on a pull request to jsonSchema.

Ideally I'd like to use jsonSchema and just fix whatever issues I run into as I go, but if folks are uncomfortable with the implications of the above issues I could alternatively rip it out and try to generate json-schema directly from the wsdoc metadata.  Thoughts?

UPDATE 1: I have submitted another pull request to FasterXML/jackson-module-jsonSchema  to address issue (3) above (dealing with recursive DTO's).

UPDATE 2: The fixes I submitted to FasterXML/jackson-moduleSchema to resolve both issues (2) and (3) above have been committed and will be included in version 2.4.1 of that module.
The dependency on 2.4.0-rc4-SNAPSHOT should not have had to be included, I can revert that from the changeset for now I think.  These are needed to bring in some patches I submitted to Jackson which have been committed and will be included in their 2.4.1 dot release (due in the next couple of weeks?).