Cancel command

Add more documentation.
Refactor code and adjust output to user.

Use the new emptyResponse() method

Allow backwards compatibility when managing only one channel.

Correct typos and minor code styling.

New command structure alpha

Rename test Helpers class to TestHelpers.

Fix missing namespace use.

Set default log verbosity on object creation to prevent potentially overwriting the value when calling setLogRequests().

Fix getUpdate handler to incorporate new Update processing.
execute() method for ALL commands must now return a ServerResponse object, not a bool!!
handle() now returns a bool, handleGetUpdates() still returns a ServerResponse object.