Boost 1.28.0 released

Boost release 1.28.0 is available.  See the www.boost.org home page for 
news of what's in the release, how to download, and how to build. (Remember 
that only the Python, Regex, and Thread libraries currently require a 
build; the others are entirely implemented in the headers.)

This is a major release, with both new libraries and lots of general 
improvements.  Much effort has gone into smoothing out the build process 
for those who use the Python, Regex, and Thread libraries.

Among other changes, the release .zip and .tar.gz files are being built via 
a new procedure, using CVS export.  Please let me know right away if you 
have any problems with either file.

--Beman