gst/base/gstbasesrc.*: Add a gboolean to decide when to push out a discont.

gst/base/gstbasesrc.*: Add a gboolean to decide when to push out a discont.

Original commit message from CVS:
* gst/base/gstbasesrc.c: (gst_base_src_init),
(gst_base_src_do_seek), (gst_base_src_loop), (gst_base_src_start):
* gst/base/gstbasesrc.h:
Add a gboolean to decide when to push out a discont.

* gst/gstqueue.c: (gst_queue_handle_sink_event), (gst_queue_chain),
(gst_queue_loop), (gst_queue_handle_src_query),
(gst_queue_sink_activate_push), (gst_queue_src_activate_push),
(gst_queue_set_property), (gst_queue_get_property):
Some cleanups.

* tests/threadstate/threadstate1.c: (main):
Make a thread test compile and run... very silly..