Initial proposal for DeltaInstanceInfo
Adding a forChanges in DeltaInstanceInfo to return stream of Delta ChangeNotifications
Cleaned up tests a little
Another implementation of delta and deltaInstanceInfo
Increasing heartbeatLatch await time for test case.
update comments
Reworked delta (for InstanceInfo)
Use interface TypeVariable instead of proprietary Impl
Merge pull request #169 from qiangdavidliu/2.x

Initial proposal for DeltaInstanceInfo
Merge #171 with 2.x latest commit.

Conflicts:
	eureka-server/src/test/java/com/netflix/eureka/server/transport/registration/protocol/asynchronous/AsyncRegistrationServerTest.java