Change implementation of SerializedTaskInvoker to be non-blocking.
Merge branch '2.x' into workspace

Conflicts:
	eureka-core/src/main/java/com/netflix/eureka2/utils/SerializedTaskInvoker.java
Minor update in eviction queue handling + related unit tests.
Add eviction queue/self preservation metrics + configuration parameters.
Merge branch '2.x' into workspace
Merge pull request #258 from tbak/2.x

2.x multiple changes