gst/gstpadtemplate.c: Add "name-template", "direction", "presence" and "caps" properties, so that gst_pad_template_ne...

Original commit message from CVS:
* gst/gstpadtemplate.c:
(gst_pad_template_class_init), (gst_static_pad_template_get),
(gst_pad_template_new), (gst_pad_template_pad_created),
(gst_pad_template_set_property), (gst_pad_template_get_property):
Add "name-template", "direction", "presence" and "caps" properties,
so that gst_pad_template_new() is just a thin wrapper around
g_object_new(), which is better for bindings. (Fixes: #539772)