'Detect new plugins and update the registry
@param reset_all: reset all entries in the registry'

@classmethod
def detect(cls, reset_all=False):

    default = (None, None)
    if reset_all:
        plugin = (lambda name: default)
    else:
        registry = cls._registry()
        plugin = (lambda name: registry.get(name, default))
    plugins = dict(((name, plugin(name)) for name in cls._scan()))
    cls._registry(plugins)
