plugins/elements/gsttee.c: Be a lot smarter when deciding what srcpad to use for...

plugins/elements/gsttee.c: Be a lot smarter when deciding what srcpad to use for proxying the buffer_alloc. Also hand...

Original commit message from CVS:
* plugins/elements/gsttee.c: (gst_tee_base_init),
(gst_tee_request_new_pad), (gst_tee_release_pad),
(gst_tee_find_buffer_alloc), (gst_tee_buffer_alloc),
(gst_tee_do_push), (clear_pads), (gst_tee_handle_buffer),
(gst_tee_chain):
Be a lot smarter when deciding what srcpad to use for proxying
the buffer_alloc. Also handle pad added/removed when doing so.
Fixes #357959.
Keep track of what pads we already pushed on in case we have pads
added/removed while pushing. Fixes #374639
* tests/check/Makefile.am:
* tests/check/elements/tee.c: (handoff), (GST_START_TEST),
(tee_suite):
Added unit test for pad resync.