CmdLine util update based on previous review comments

Updated command line util based on review comments
Handle port number conflict case. To make sure the right port number is
picked up when Tracking URI is registered, inject HttpServer into
HttpTrackingURLProvider. Start the Jetty server in HttpServer
constructor. This is to ensure the resolved port number is picked up by
HttpTrackingURLProvider regardless HttpTrackingURLProvider is registered
first or RuntimeStartHandler is run first.
Merge branch 'master' of https://github.com/Microsoft-CISL/REEF into juwang-httpServer2
Update for review comments
update for final variables for server and port
throw exception if cannot resolve port number conflict after maxAttempt

throw exception if cannot resolve port number conflict after maxAttempt
Use named parameters for  min/max/maxAttempts

Use named parameters for  min/max/maxAttempts in HttpServer
Add HttpServerImple as default implementation
Updated test cases accordinly
Merge pull request #784 from Microsoft-CISL/juwang-httpServer2

Dynamic port number assignment for the HTTP server and various small fixes