Update gmaven to gmavenplus plugin

Updated to newer groovy maven plus plugin
Switch from deprecated ant 'tasks' to ant 'target' maven xml tags
Merge pull request #203 from hazendaz/master

Update gmaven to gmavenplus plugin
Moving access request log configuration in to its own method to allow extension
Make prepareForDeferredProcessing on AccessEvent idempotent, otherwise the OutputStreamAppender overwrites valid properties with now invalid properties when using an async appender
Merge pull request #201 from reines/request_log_configuration

Moving access request log configuration in to its own method to allow extension
Merge pull request #202 from reines/idempotent_deferred_access_event
Merge pull request #202 from reines/idempotent_deferred_access_event
Update CONTRIBUTING.md

Warn users against adding their release notes to news.html since that
always causes merge conflicts.
Merge pull request #193 from SierraGolf/sierragolf/LOGBACK-977

LOGBACK-977 - AbstractSocketAppender loses event for every socket connection break
Update release notes for 1.1.3

Add notes for #193 (LOBGACK-977), provided by Sebastian Gröbler
Update release notes for 1.1.3

Added note for LOGBACK-128
Fix AsyncAppender/SocketAppender unit tests

AsyncAppenderBaseTest: The appender was not allowed enough time to
flush the appender on #stop(), causing the empty-check of the appender's
queue to fail. The test appender's max-flush time is now extended from
30ms to >1000ms.

AbstractSocketAppenderIntegrationTest: A unit test expected
deque.takeFirst() to be called only once after a log-event is appended,
but the call actually occurs twice in a while-loop, where the second
call is intended to block, waiting for the next log-event.

AbstractSocketAppenderTest: A unit test that verified appender
behavior when its deque was at capacity neglected to fill the deque
before testing for errors.
specified locale (country + language) and timezone for surefire execution to have constant non-user-specific settings
fixed broken test setup for addsInfoMessageWhenEventIsBeingDroppedBecauseOfConnectionProblemAndDequeCapacityLimitReached
removed unnecessary spawn of a connector thread
promoted socket connector to become a member to reduce overhead when creating socket connection
simplified socket re-connection logic
added missing unit test for re-establishing the socket connection when stream creation fails with IOException
added additional unit tests for stopping socket appender task on interrupts
removed unnecessary TODO comment