Fix issue 2245. aifc now skips any chunk type it doesn't actually

process instead of throwing errors for anything not in an explicit
skip list.  This is per this spec: http://www.cnpbagwell.com/aiff-c.txt.
Spec reference and test sound file provided by Santiago Peresón, fix
based on patch by Hiroaki Kawai.

Lib/test/test_sundry.py

@@ -11,7 +11,6 @@ class TestUntestedModules(unittest.TestCase):
         with warnings.catch_warnings():
             warnings.simplefilter("ignore")
             import CGIHTTPServer
-            import aifc
             import audiodev
             import bdb
             import cgitb