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.

Remove $command from commands, not needed.
Minor docblock corrections.

Rewrite custom JSON input for debugging. Remove custom JSON input in handle() method.
Fix issue that disabled or invalid commands died silently. Always output some "Command not found" message.