gst/gstpad.c: Added simple version of improved caps checking. It was previously assum...

gst/gstpad.c: Added simple version of improved caps checking. It was previously assumed that a setcaps function would...

Original commit message from CVS:
* gst/gstpad.c: (gst_pad_get_caps_unlocked),
(gst_pad_acceptcaps_default), (gst_pad_configure_sink),
(gst_pad_configure_src):
Added simple version of improved caps checking. It was previously
assumed that a setcaps function would check the validity of the caps but
people prefer us to check caps against the template automatically.
Fixes #421543.