Change following files, path given from source top level directory
  configure.in: GIACLIB_MAJOR_VERSION=0 GIACLIB_MINOR_VERSION=3 GIACLIB_MICRO_VERSION=0
  giac.specs, giac.specs32: version/release
  debian/changelog, debianold/changelog
  mkdebian
  If you have links, update them, e.g.
  cd ..
  rm doc
  ln -s giac-0.3.x/doc
  
  etc...