The specification of the "group" argument to the java.lang.Thread constructor
is incorrect. It says that if group==null, "the new process belongs to the
same group as the thread that is creating the new thread".

In reality, if a SecurityManager is installed (as in appletviewer), if
group==null, the new thread will belong to the group returned from the
SecurityManager's getThreadGroup() method.

This specification should be updated to match reality.