gst.supp: A whole bunch of suppressions detected on latest gentoo ~amd64.

gst.supp: A whole bunch of suppressions detected on latest gentoo ~amd64.

Original commit message from CVS:
* gst.supp:
A whole bunch of suppressions detected on latest gentoo ~amd64.
Make some existing suppressions more generic (for subtle dependecy
code changes).
Added suppressions for glibc-2.9.
Added suppressions for new variants of ALSA leaks.
Added suppressions for a series of leaks in plugins registrations due
to some pad templates' caps calculated at runtime.
Added suppressions for variants of some leaks in pango/fontconfig.
Added suppressions for leak in gstffmpegcsp.c (nothing we can do
about it, but will only exist once).