SBCL kindly offered suggestions for improvement:

SBCL kindly offered suggestions for improvement:
 - Use 'defgeneric' with ':method' for things that are meant to
   have just a single method.
 - Lose some unreachable code in the parser.
 - Weak hash tables in SBCL need to use ':weakness :value'.
 - The wire-level stuff can use some more type declarations.
 - Fix a package problem in one of the examples.

Passes 'precheckin' with the new Protobufs unit tests in place.

git-svn-id: http://svn.internal.itasoftware.com/svn/ita/trunk/qres/lisp/quux/protobufs@547515 f8382938-511b-0410-9cdd-bb47b084005c