Test suite stability: Rest Store changes

* Always close all EmbeddedCacheManager
* Mark all methods unstable in RestStoreTest (see comment in code)
* Fixed test name
Test suite stability: Mark as unstable the following tests:

* AsyncStoreTest.testPutClearPut (ISPN-3988)
* L1StateTransferRemovesValueTest.testStateTransferWithL1InvalidationAboutToBeCommitted (ISPN-3989)
* AtomicMapAPITest.testConcurrentTx (ISPN-3990)
* RepeatableReadAtomicMapAPITest.testConcurrentTx (ISPN-3990)
* DistSyncTx1PCL1FuncTest.testBackupOwnerInvalidatesL1WhenPrimaryIsUnaware (ISPN-3991)
* ReplSyncDistributedExecutorTest.testBasicTargetRemoteDistributedCallableWithHighFutureAndLowTaskTimeout (ISPN-3992)
* IntegrationTest.testAsyncAddRemove (ISPN-3994)
* AsyncDistExtendedStatisticTest.testReplaceWithOldVal (ISPN-3995)
Revert changes in TreeProfileTest and HotRodBigDataStressTest

* only unit,functional,arquillian,xsite test groups should be
mark as unstable since the other test groups are running manually.