avro

AVRO-1039. C: Don't try to use nonexistent codecs in test cases.

The quickstop example was hard-coded to use the deflate codec, even if
we're not building that codec.  The null codec will always be there, so
we fall back on that if we don't have deflate.


git-svn-id: https://svn.apache.org/repos/asf/avro/trunk@1295401 13f79535-47bb-0310-9956-ffa450edef68