Make DISCARD collections thread-safe
Keep track of ignored members even when they're not in the view any more.
Merge pull request #184 from danberindei/t_DISCARD

Make DISCARD collections thread-safe + Keep track of ignored members even when they're not in the view any more
Sending cache information to others if discovery protocol is static and coord and enabled (https://issues.jboss.org/browse/JGRP-1903)
pp for Probe
Added accessors for custom log factory
NAKACK2: added resend_last_seqno flag (https://issues.jboss.org/browse/JGRP-1904)
Attempt to fix the tests in Maven

I configured the surefire plugin but it doesn't seem to know how to run
each XML test suite in its own JVM, with its own settings. Group filtering
doesn't work either, so it just runs all the tests in one go.

That results in an OutOfMemoryError, so I disabled tests by default.