Don't use Promises for chaining Shepherd result handlers

Hello @nicks, 

Tested against medium2 unit and functional tests.

Please review the following commits I made in branch 'kyle-callbacks'.

018f01f751c41a0a03fb25440bded1fd9b66739f (2013-08-01 16:58:51 -0700)
Remove promises as method of chaining handlers


R=@nicks