plugins/elements/gsttypefindelement.*: Cleanup properties.

plugins/elements/gsttypefindelement.*: Cleanup properties.

Original commit message from CVS:
* plugins/elements/gsttypefindelement.c:
(gst_type_find_element_class_init),
(gst_type_find_element_set_property),
(gst_type_find_element_get_property),
(gst_type_find_element_activate):
* plugins/elements/gsttypefindelement.h:
Cleanup properties.
Fix pad leak when peer query fails.
We can still typefind when the peer returns -1.
Add property to force caps and bypass typefinding. This will be used in
uridecodebin.
API::force-caps