add test for amrnbenc, enable test infrastructure, and fix a leak

add test for amrnbenc, enable test infrastructure, and fix a leak

Original commit message from CVS:
add test for amrnbenc, enable test infrastructure, and fix a leak

* common/check.mak:
allow for specifying more than one suppressions file in SUPPRESSIONS
* Makefile.am:
* tests/Makefile.am:
* tests/check/.cvsignore:
* tests/check/Makefile.am:
* tests/check/elements/.cvsignore:
* configure.ac:
add tests/check
* tests/check/gst-plugins-ugly.supp:
add suppressions for libs used by -ugly
* tests/check/elements/amrnbenc.c: (buffer_new), (buffer_unref),
(setup_amrnbenc), (cleanup_amrnbenc), (push_data),
(GST_START_TEST), (amrnbenc_suite), (main):
add a simple test for encoding amr
* ext/amrnb/amrnbenc.c: (gst_amrnbenc_init):
fix pad template leaks