DTI/TDI comparison ops with incompatible types
Timestamp and Timedelta comparisons against non-Timestamp/Timedelta-like others return False for `__eq__`, True for `__ne__` and raise `TypeError` for inequalities.  DatetimeIndex follows this convention in _some_ cases, but there are paths that will end up raising instead of returning True/False.  TimedeltaIndex doesn't follow this convention at all.

Is the current hodge-podge intentional?  If not I can put together a PR to ensure that `index.__cmp__(other) == np.array([index[n].__cmp__(other) for n in range(len(index))])`