1.  Made <choice> element optional in <launch:create> to allow
       passing just the <launch:phase> in <launch:create> per request
       from Ben Levac.
   2.  Added optional "type" attribute in <launch:create> to enable the
       client to explicitly define the desired type of object
       (application or registration) to create to all forms of the
       create extension.
   3.  Added text that the server SHOULD validate the <launch:phase>
       element in the Launch Phases section.
   4.  Add the "General Create Form" to the create command extension to
       support the request from Ben Levac.
   5.  Updated the text for the Poll Messaging section based on feedback
       from Klaus Malorny.