a more aggressive tactic to recover from an unparseable XID packet.  This commit applies the patch by Jared Roberts <harmonic.ressonance@gmail.com>

(patch forwarded by @yarikoptic) which was provided in an email to psychopy-users@googlegroups.com, subject "Re: [psychopy-users] pyxid bug patch", dated Wed, 16 Oct 2013 13:11:47 -0400