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
Updated the error messages for Resource Manager reported Container Failure
This closes #767: The exception sent to the user code when the resource manager reports a failed or closed Container are now more legible and give a clearer explanation of what actually happened.
Created reef-examples-clr
 * Added a new submodule `reef-examples-clr`
 * Moved the CLR examples to that new module
 * Removed the CLR examples from `reef-examples`
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
update retainedEvalCLR files location
Merge pull request #787 from Microsoft-CISL/weimer_767

Updated the error messages for Resource Manager reported Container Failure
Merge pull request #790 from Microsoft-CISL/weimer_yingda_clr_examples

update retainedEvalCLR files location
Merge branch 'master' of github.com:Microsoft-CISL/REEF into weimer_clr_examples
Merge branch 'weimer_clr_examples' of github.com:Microsoft-CISL/REEF into weimer_clr_examples
Merge pull request #784 from Microsoft-CISL/juwang-httpServer2

Dynamic port number assignment for the HTTP server and various small fixes
Merge branch 'master' of github.com:Microsoft-CISL/REEF
merge with master