add new "overspin_algorithm" option to handle what happens

when a star is spinning faster than it can

currently there are two options:
OVERSPIN_BSE transfers the excess angular momentum back to the orbit,
       so is conservative in that no mass or angular momentum is lost.

OVERSPIN_MASSLOSS uses the rotationally_enhanced_mass_loss formalism
       given below to remove material which reduces the star's spin.

Also removed the ROTATIONALLY_ENHANCED_MASS_LOSS compile define,
because this functionality is now required always.