Added connection creation timer. Use static ScheduledThreadPoolExecutor for all DynamicServerListLoadBalancer instances with configurable core thread pool size.

Fix RestClient connection leaks when it throws ClientException upon server throttle. Enhanced JUnit tests for RestClient retries.

Added more API to query executeWithBackupRequests() results. Make sure cancel works correctly. Close the consumer as part of response.close().

Add statics (counters) to measure the efficiency of the default connection pool manager used in Ribbon's httpclient. Upgrade httpclient version t0 4.2.1.