[DrJava] update build-common.xml and dynamicjava.jar

[James I-C. H. <jh...@ow...>]

We've added a task in build-common.xml to compile DrJava while displaying
unchecked error messages so you'll have to cvs update it.

Update dynamicjava.jar in the lib directory as well because there was a
bug which caused a test to fail in OSX.

James