Register a matcher associated to one or more aliases. Each alias
        given is also normalized.

def register(matcher, *aliases):
    """ Register a matcher associated to one or more aliases. Each alias
        given is also normalized.
    """
    docstr = matcher.__doc__ if matcher.__doc__ is not None else ''
    helpmatchers[matcher] = docstr.strip()

    for alias in aliases:
        matchers[alias] = matcher
        # Map a normalized version of the alias
        norm = normalize(alias)
        normalized[norm] = alias
        # Map a version without snake case
        norm = norm.replace('_', '')
        normalized[norm] = alias