SES-1943 ParsedQuery.toString now outputs Dataset if present (FROM/FROM
NAMED clauses).
SES-1941 : Do not cache blank node identifiers if they are preserved
Merged in ses-1943 (pull request #205)

SES-1943 ParsedQuery.toString now outputs Dataset if present (FROM/FROM NAMED)
SES-1941 : Use UUID instead of map to ensure global uniqueness

Generate a single UUID for each run (reset using clear() by parsers
after each run), and use it instead of a map to maintain blank node
identity between calls to RDFParserBase.createBNode(String)
Merged in SES-1941 (pull request #206)

SES-1941 : Do not cache blank node identifiers if they are preserved