Various fixes to the debug tools for AP,CKAN,RDF.

* [AP_TABLE,FIX] Internal server error when empty table / no automated processes.
* [AP_TABLE,EXT] Added visualization of filter AP stages.
* [DIR_EXT,FIX] Added default option for directory_files/3: `include_self(boolean)`.
* [RDF_NAME,FIX] Term writing did not use write_canonical_catch/1 yet.
* [RDF_READ,FIX,DOC] Typo in documentation.
* [RDF_TABULAR_TERM,EXT] Add visualization of class resources.
* [RDF_TABULAR_TERM,FIX] Graph index would break predicate term display.