gst/base/gstbasetransform.c: The event virtual method is now properly implemented...

gst/base/gstbasetransform.c: The event virtual method is now properly implemented, with a default handler

Original commit message from CVS:
* gst/base/gstbasetransform.c: (gst_base_transform_class_init),
(gst_base_transform_event), (gst_base_transform_eventfunc):
The event virtual method is now properly implemented, with a default
handler
Sub classes should call the parent_class event method. They should
return FALSE if they had a problem handling the given event, or don't
want GstBaseTransform to send that even downstream
* gst/elements/gstidentity.c: (gst_identity_class_init),
(gst_identity_init), (gst_identity_event),
(gst_identity_transform_ip), (gst_identity_set_property),
(gst_identity_get_property):
* gst/elements/gstidentity.h:
Added the single-segment boolean property.
If set to TRUE, it will output a single segment of data, starting from
0, will eat up all incoming newsegment, and modify the timestamp of the
buffers accordingly