Remove version number from README file

This is a change in the way I'm storing things; I want the version info
to be generated on the fly and not contained in the repo, except in the
NEWS.md file.
Remove version info from repository

This patch uses git shell commands to set the date and version in each
LaTeX file on-the-fly.  It introduces the 'ver' target for the makefile,
which writes the current date and version to an unversioned file
'VERSION.tex' (the name choice might not be the most intuitive...) and
the LaTeX file imports it to set the date and version.