For the next release, I'm probably going to move to a Maven-like project layout (src/main, src/test, etc.), and when that happens I think I'll put the RSyntaxTextArea demo code in the main project, and the AutoComplete demo code in that project. I *think* that's kosher (e.g. something like src/demo/java/**).
I actually thought I had released that code previously, on SourceForge, but it looks like I haven't.
Really, another good set of examples for AutoComplete (which you may have found) is the RSTALanguageSupport stuff (either on SourceForge