Improvements to Gibbs models.

   envelope.R
      Bug fix: envelope.ppm crashed if global=TRUE and savefuns=TRUE.

   tests/envelope.R
      Added tests for bug.

   ppmclass.R
   summary.ppm.R
      Output now states whether the model is valid.

   ppmclass.R
   valid.ppm.Rd
      valid.ppm has new argument 'warn'

   fiksel.R
      Bug fix in validity checker $valid()

   terse.R
      New internal function ruletextline()

   ppmclass.R
   summary.ppm.R
      Output now respects options('width')

   aaaa.R
   multihard.R
   multistrauss.R
   multistrhard.R
      Improved output of self-documenting functions

   NEWS
   DESCRIPTION
    updated.
    Temporary version number: 1.39-1.005
    (patch levels are now fractional, and rounded upwards)