Removed definitions of 'Distribute' and 'Distributor'.

The definition of 'Distribute' did not really do very much. Taking it
out makes 'Distributor' unnecessary; the only remaining references to
'Distributor' were in the disclaimer provisions where they can be
substituted with 'distributor of My Work'. (Note that any mere
licensee-distributor must be distributing an upstream 'My Work' by
definition.)