The code was using the HTTP Header "Accept" parameter as primary for the
returning document type. This clashed when a user explicitly used the
GET['format'] attribute.

Now the GET['format'], when valid, has priority over the HTTP Accept
Refactors validateMimeType usage
still fixing the insert action
Returns the full triple description
Adds a 'depth' parameter to the '/resource', '/page', '/data' services
to limit the details in the triple description

Improves the use_case test examples adding "author" and "title"
parameters in case of DOI elements

Improves the ICD document adding example both in turtle and json-ld
format.
Preliminary OpenSearch implementation: 
- return rdf/json/turtle
- search "title"