Started working on IGNITE-890 and IGNITE-1100

[Denis Magda]

IGNITE-890 (Inconsistent discovery events happened in test):
https://issues.apache.org/jira/browse/IGNITE-890
IGNITE-1100 (TcpDiscoveryMultiTreadedTest.testMultiThreaded() fails):
https://issues.apache.org/jira/browse/IGNITE-1100

These two issue should fail because of the same bug or almost identical
bugs in the code. Thus start working on them in parallel.

--
Denis