Allow OSC message sends without magic bundle wrapper

Automagically wrapping simple message sends is often superfluous as bundles are for controlling when the 0-n included messages should be executed and that they be executed atomically - in the simple single message case, that is overkill as only immediate mode is supported and there is only a single message so the atomic execution doesn't do anything. Even more so, the Cinder OSC wrapper doesn't provide separate callbacks for message vs bundle receives, so I would suspect that changing the default to not wrapping wouldn't be bothersome for Cinder to Cinder OSC communication, and at worst for those that wanted the existing behavior, an inconvenience of adding an additional parameter to their `sendMessage` calls.

This is inline with a change requested in openFrameworks [issue #1804](https://github.com/openframeworks/openFrameworks/issues/1804#issuecomment-22424973) and [PR #2438](https://github.com/openframeworks/openFrameworks/pull/2438) where the same argument was made for why  bundle wrapping should be optional (at best) and why it should default to not wrapping.