Fix make clean for test targets.
Fix make clean for test targets.

* Makefile.in
  (clean): Add missing objects from the test tree.

Submitted by: Brandon Ehle
Tweaked by: Justin Erenkrantz


git-svn-id: 683495cb1553624b05a54e2ba9533425f69cf277@1084 61a7d7f5-40b7-0310-9c16-bb0ea8cb1845

coapp-packages/serf,coapp-packages/serf,coapp-packages/serf