add test op to cl-json
add test op to cl-json

Made it easier to test cl-json by adding an asdf test-op to the asdf
system definition, and providing a PERFORM method for it.

Now one can simply say (asdf:oos 'asdf:test-op :cl-json) to load
the system and run the FiveAM based tests.

darcs-hash:20100102211745-b37ea-13f70c0f95cff41a2f07a1c67af9ccdf83559a32.gz

hankhero/cl-json