Remove support for 'old' syntax mechanisms

All JNode commands that used the 'old' syntax mechanism were converted to the 'new' mechanism months ago. I now want to remove the code that supports the 'old' syntax, since the cost of maintaining it is (IMO) no longer justifiable. In particular, the incestuous relationship between the old syntax code and the help code is proving to be problematic for some refactoring I'm doing to enable ESC help.

If there are no objections, I will remove old Syntax support next weekend. In the meantime, the changes I'll be checking in later today appear (based on unit test evidence) to break completion for old syntax commands.