Ensured orcid ID path is being used where it should be instead of value
property.
Created new orcid-identifier element to allow orcid-id to remain as is
for JSON backwards compatibility.
Tidied up a load of related oddities.
Merge pull request #682 from ORCID/fixOrcidIdValueVersusPathInconsistencies

Fix orcid id value versus path inconsistencies