Port of r16181 from libvorbis.
Port of r16181 from libvorbis.

First half of fix for https://bugzilla.mozilla.org/show_bug.cgi?id=500254
Residue code was not checking that its partition books were books with
 specified/populated value mappings.


git-svn-id: aaacb87f8b65fb7d6fc622a2ff2a583ecedb130f@17522 0101bb08-14d6-0310-b084-bc0e0c8e3800

soundcloud/tremor,soundcloud/tremor