complicated string of pointers, it's now just a global block of text that gets
appended to as the error is being thrown up, and can be displayed at the catch
point if desired. There are almost no cases where a thrown exception will not
result in an error message being displayed to the user.
old system (for example, the meaning of 'a') has yet to be restored. In the
new scheme, this will be done by definition a function outside of the value
expression logic, rather than the tight coupling between journal innards and
value expressions that occurred in 2.x.
XML-related bits -- I just wanted the better infrastructure that had been
created during the rewrite. It doesn't work, but it compiles and links now.
This means that all of the previous 3.0 code has been moved over, although
there are still snippets of code in pending/old that need to be restored.
