replace the value of the fallback definition of M_PI with
the one from glibc. Ours was actually off by 3 in the last
digit, beyond the float precision boundary.
thanks to Brian Havard for pointing out the discrepancy.
also .cvsignore fix for vq/
git-svn-id: http://svn.xiph.org/trunk/vorbis@1111 0101bb08-14d6-0310-b084-bc0e0c8e3800