removed RFC3066 from localbiblio

Use BCP47 instead
updated previous URL to reflect JSON variant
updated Abstract section
updated Intro and Conformance sections
Updated document structure
added mapping for core tabular data
Part-way through updates to annotated tab-data
added note about Ivan's original text
Merge pull request #99 from 6a6d74/json-edit

Updates to JSON mapping document (part 1)