Action API improvements

[dread]

Focusing on improving Action API as the v3 API:

• have an optional parameter of the data_dict called "options". Options would contain items that would get passed into the context. e.g. {"options" : {"ref_package_by": "id"}}.
• instead of using API version to change the way packages are referenced, use the ref_package_by.
• All package_show, group_show etc. to accept an object 'name' as an alternative to object 'id'.
• Action API is v3 of api, replacement for v1 & v2. Default for most urls is still v1, but if url is /api/action then default to v3.

Next steps:

• Add search API (package, resource,
• Add Util API
• Clarify JSONP still applies
• Add doc strings, clarifying parameters