Return detail information about a failure of an HTTP API call

[hyangtack]

When an exception is raised during processing an HTTP API request, a client might want to get the exception in order to get detail information why the request was failed. One option is returning stack trace to the client via HTTP response.

[hyangtack]

How about:

• Adding verboseHttpResponses flag to CentralDogmaConfig (false by default)
• Defining an error response class:

class ErrorResponse {
	String timestamp;
	String requestedPath;
	String message;
	List<Error> errors;
	List<StackInfo> trace;
}

class Error {
	String resource;	// project, repository, entry, revision, token
	String type;		// conflict, existence, nonexistence
	String target;		// the name of project/repository/entry, revision or token ID
}

..., but it would be better to handle this issue when implementing the HTTP API based client.