Merge branch 'origin/2.7.x'

Conflicts:
	core/model/src/main/java/org/openrdf/model/vocabulary/FOAF.java
	core/rio/turtle/src/main/java/org/openrdf/rio/turtle/TurtleParser.java
	testsuites/sparql/src/main/java/org/openrdf/query/parser/sparql/ComplexSPARQLQueryTest.java
	testsuites/sparql/src/main/java/org/openrdf/query/parser/sparql/SPARQLUpdateTest.java
fixed missing import after merge
several parse errors related to QName/IRI processing made fatal
SES-1736 updated to latest official w3c Turtle test suite (available
from http://www.w3.org/2013/TurtleTests/)
SES-1736 SES-1862 including unit tests for easier testing/debugging,
partial fixes in turtle grammar to address special chars in prefixed
names.
SES-1736 added unit test for prefix parsing based on w3c test
Merge remote-tracking branch 'bitbucket/2.7.x' into SES-1736
SES-1736 : Update test to include new directive case matching setting