- Alignments are now returned in sets of alignment pairs and sets of identity sets.
- RDF content type handling unified.

* [OAEI,EXT] Improvements to reading/writing alignment results, including the relation and measure properties.
* [OAEI,FIX] Reading alignments from graph/file now returns an ordered set of pairs.
* [RDF_CONVERT,EXT] Added the overwrite option for the RDF file and directory conversion predicates.
* [RDF_CONVERT,SC] Added predicate options declarations.
* [RDF_FILE_DB,NEW] Added rdf_content_type/1.
* [RDF_FILE_DB,SC] Integrate the formats that occur in the old rdf_content_type/2. The new rdf_content_type/2 is based on rdf_serialization/5 and replaces rdf_mime/1 and rdf_mime_format/2 s well.
* [RDF_FILE_DB,SC] Renamed rdf_extension/1 to rdf_file_extension/1.
* [RDF_FILE_DB,NEW] Added rdf_file_extension/2.
* [RDF_META,SC] Added predicate options declarations.
* [OAEI,SC] Removed unused debug message.