Use new \release{}; this is now separate from \date{}.

Use \email{} instead of \code{} for email addresses.

have to do that one!), but at least the version will match the release
version.  (1.5a2 got skipped for this.)

Added copyright.tex to all files.
Added descr of check_interval to libsys.tex.
Corrected lotsa typos in tut.tex (thanks to George M. Sipe).
Corrected mktuple (should be newtupleobject) example in ext.tex.