document gst_caps_debug change gst_caps_debug to accept a label argument, assists...

document gst_caps_debug change gst_caps_debug to accept a label argument, assists greatly in debugging capsnego bette...

Original commit message from CVS:
* document gst_caps_debug
* change gst_caps_debug to accept a label argument, assists greatly
in debugging capsnego
* better names from gst_object_name_default
* some more debugging in gstpad.c
* require caps to match padtemplates on both side of a connection
* gstspider uses default naming so that names are globally unique
* moved filesrc offset arg to the top -- show up first in a prop list.
in the future we should have flags on props indicating which ones
it might be interesting for the end-user to change.
* initialize cothreads in the more standard way, and provide some more debugging