SES-1882 test case and fix for isolation problem in in-memory store.
SES-1882 : Remove unused imports accidentally added
SES-1882 simplified by taking out unnecessary check on active lock
SES-2028 fix for concurrency issue in Native Store. Only change is that
we check if the transaction lock has been acquired by this Connection -
if not we only read committed triples.
SES-2025 better handling in case of uncommitted results in another
connection. cleaned up tests.
SES-2028 logic and name of transactionLockActive method now in sync.
SES-1882 SES-2028 SES-2025 disabled isolation tests for HTTP
connections.
SES-1039 handleClose and run method now acquire explicit lock when
using/dereferencing the parserThread object.
SES-1039 handleClose and run method now acquire explicit lock when
using/dereferencing the parserThread object.
Merge branch 'ses-1039' of ssh://bitbucket.org/openrdf/sesame into
ses-1039

Conflicts:
	core/http/client/src/main/java/org/openrdf/http/client/BackgroundTupleResult.java
SES-1039 undo of unintended commit
SES-1990 SPARQL parser now dumps INSERT DATA/DELETE DATA data block as
raw string, parsing is left to dedicated parser (subtype of TriG parser)
as part of SailUpdateExecutor.
SES-1990 fixed handling of named graph/context in case of removal
SES-1990 various fixes to make compliance tests greenline.
SES-1990 fixes in negative syntax parser tests
SES-1990 minor cleanup in grammar
SES-1990 minor cleanup in javadoc, added override annotation.
Clean up potential NullPointerExceptions.

In cases where a value has been checked for null-ness but then
used, prefer an explicit exception to an inevitable NPE.
Allow exceptions to propagate in ComplexSPARQLQueryTest.

Allow exceptions to cause tests failure, rather than catching them
and manually calling fail(): the test runner will report the same
thing anyway. This saves a few hundred lines, simplifies the tests
and also satisfies Eclipse's null analysis that later lines
won't cause an NPE.
SES-1786: Set the classloader to prevent multiple instances of Logback.

Set the webapp classloader to prefer classes from the parent
classloader, so only the test instance of StaticLoggerBinder is used.