1.9.0 progress

[David Sugar]

I had such rapid progress on the new 1.9.0 code base for the 2.0 release
that I am going to bypass 1.7.0 and I expect 1.9.0 to be ready in a day or
two.  This adds namespace support and std::exception based exception
handling.  Rather than absort two sets of changes over time with the
unified source directory and the exception/namespace stuff, I am going to
release both at once...

David