check/Makefile.am: add two more tests for valgrinding

check/Makefile.am: add two more tests for valgrinding

Original commit message from CVS:
* check/Makefile.am:
add two more tests for valgrinding
* check/gst/gstvalue.c: (GST_START_TEST):
test refcount of deserialized buffer, found a leak
* docs/gst/gstreamer-docs.sgml:
* docs/gst/gstreamer-sections.txt:
* docs/gst/gstreamer.types:
* docs/gst/tmpl/gstminiobject.sgml:
add miniobject to docs
* gst/gstminiobject.c:
add some docs
* gst/gstvalue.c: (gst_value_deserialize_buffer),
(gst_string_unwrap):
fix a hard-to-find invalid write for one of the tests
fix a leak for deserialized buffers