Various improvments and bug fixes.

   ppmclass.R
      print.ppm no longer computes variances
      if the model was fitted with method='logi', VB=FALSE.

   evalcovar.R
   spatstat-internal.Rd
      evalCovar has new argument 'lambdatype' passed to predict.ppm

   cdftest.R
   cdf.test.Rd
   spatstat-internal.Rd
      cdf.test.ppm and cdf.test.lppm now handle Gibbs models
      and perform a Monte Carlo test.

   lurking.R
   lurking.Rd
      lurking variable plot can now include simulation envelopes.

   diagnoseppm.R
   diagnose.ppm.Rd
   spatstat-internal.Rd
      diagnose.ppm can now produce simulation envelopes.

   weights.R
      bug fixes

   lurking.R
      Fixed bug arising in rare cases.

   NEWS
   DESCRIPTION
    updated.
    Temporary version number: 1.39-1.020