Added the 'get_partitions', 'nth_linear_recurrence' and 'nth_linear_recurrence_with_modulo' operators.

Added 'from_ethiopian', 'to_ethopian' and 'to_ethiopian_name' functions for the Ethiopian calendar.

Added 'black_hole_surface_tides' now that I understand it. I also added a more general 'tidal_force' operator.

Added 'is_harmonic', 'is_antiharmonic', 'harmonic_fraction', 'alternating_harmonic_fraction', 'harmonic_residue', 'harmonic_mean', and 'antiharmonic_mean' operators.

Added 'hyperoperator' and 'hyperoperator_right' operators.

Added 'root_mean_square', 'stirling1', 'stirling2', 'ackermann', 'square_super_root', 'cube_super_root' and 'super_root' operators.

Added more unit tests and the usual bug fixes.

This is a beta release because the help text for most of the new operators is not filled in.