Fixes SES-960 - RDF Parsers Incorrectly Resolves Relative Query URIs
SES-1771 Fixed Javadoc issues in sesame-model.
Merge branch '2.7.x' of bitbucket.org:openrdf/sesame into SES-960_sesame27
Add ParsedURITest
Fixes SES-1855 DirectoryLockManager.delete Needs To Be Synchronized
Revert protected logger change in RioConfig
Add quick test to RDFXML to test a document starting with a comment

Refs https://github.com/tkurz/sesame-vocab-builder/issues/41
SES-869 replaced NOW function implementation with dedicated algebra
element to faciliate return a shared value on successive calls.
cleanup of unnecessary tracking of shared Now() instance.
SES-869 simplified solution: no need to get rid of Function
implementation or to introduce new algebra node.
removed redundant new algebra node - we are not using it after all
code cleanup
Merged in dvisser/sesame/SES-1771-sesame-model-javadoc (pull request #320)

SES-1771 Fixed Javadoc issues in sesame-model.
SES-1903 made getNextElement and handleClose synchronized to avoid possible null pointer exception.
Merged in SES-869-now-function (pull request #322)

SES-869  EvaluationStrategyImpl keeps a shared return value for successive calls of the NOW function
Merged in SES-1903-paralleljoincursor-NPE (pull request #323)

SES-1903 made getNextElement and handleClose synchronized to avoid possible null pointer exception.
Merged in SES-960_sesame27 (pull request #314)

RDF Parsers Incorrectly Resolves Relative Query URIs
Merged in SES-1855_sesame27 (pull request #321)

DirectoryLockManager$1.delete Needs To Be Synchronized