Streamline convenience overload stringize(std::wstring); make convenience
overload wstringize(std::string) symmetrically convert from UTF-8 string.
Also eliminate STRINGIZE() et al. dependency on Boost.Phoenix: use lambdas
instead.
Using lambdas instead of template expansion necessitates reordering some code
in wrapllerrs.h.
For some reason, after the upgrade to Boost 1.57, gcc 4.6.3 has trouble with
the boost::lambda::_1 usage in stringize.h. This is consistent with other
cases we've encountered in which Boost.Lambda appears to be unmaintained and
losing its compatibility with other libraries. Fortunately Phoenix provides a
functional equivalent, albeit spelled differently.
Nat Goodspeed