* [DOYLE,RDFS_ENT,TMS_PRINT,FIX] Sync with new RDF literal support.
* [PL_TERM_HTML,FIX] Support for the new HTML links.
* [RDF_LITERAL,FIX] RDF meta predicate argument.
* [RDF_LITERAL,RDF_MAT,SC] Removed unused module imports.
* [RDF_PLAIN_LITERAL,FIX] Explicit import from RDF_SIMPLE_LITERAL (private predicate). Typo. Singleton argument.
* [SET_THEORY,SC] Removed unused code.