ISPN-3197 Message ordering of Get and Invalidation can cause L1 to be inconsistent.

* Implemented single entry point for concurrent gets.
* Also support concurrent invalidation for reads with limited blocking
* Added tests for various concurrency/edge issues
ISPN-3325 ConsistentHashV1IntegrationTest.testCorrectBalancingOfKeysAfterNodeKill random failures
Remove references to version.scala in parent pom.xml

Fixes problems with IntelliJ compilation of server modules.
ISPN-3279 Delete ConfigurationOverrides and GlobalConfigurationOverrides in Spring module