Fixed a few nits with exception specifications, return type
conversion from C-string to std::string, and a few other
minor things. This should help Win32 folks a bit. Thanks to
Paul Whitehead <paul.whitehead@bcs.org.uk> for his report
of the conversion problem and an exception specification bug.
Zopyra Unit Test (ZUT) distribution now included along with many unit tests. Extensive changes to namespaces, bug fixes and re-working of the transform() function and backreferences.