when both q/sforms are unknown. Otherwise should default to
nibabel. Also added method to MelodicClassification to return all labels.

multiple topics to be specified.

instead of props.

given topic.

passed through to listener functions.

a warning if the sub-class is also a HasProperties, because both classes
define a 'notify' method, which could be super confusing.

anymore, and might get deleted.

of lenght 1.

instanceified. Image.isNeurological is now memoized.

immediatelly re-run the idle loop.

initialisation. Async.idle still honours after argument, even if a
wx application is not running.

settings.read returns any specified default value even if there is no
GUI.

Platform.canHaveGui, can be used to tell whether we are able to create a
GUI. Async modified to use platform.haveGui instead of performing its
own test.

already queued to be dropped. More useful when used through idleWhen.

events (if user stops moving the mouse), meaning that idle tasks can get
stuck in the idle queue, and not processed until the next UI
event. Therefore, the idle loop now gets periodically called by a
wx.Timer, in addition to via EVT_IDLE events.

dictate when the actual function is called.

keyword arguments.

TaskThread also doesn't crash when an enqueued task raises an error.