Bugfixes and tweaks.

   quadscheme.R
	Bug fix in pixelquad (handling multitype data)

	Suppressed redundant check in quadscheme.replicated()

   intensity.R
	Bug fix in handling multitype model with trend ~1

   relrisk.Rd
	Tweaked text

   mpl.R
	Suppressed redundant check in mpl.engine() call to quadscheme()

   predict.ppm.R
	If the result is a list of images, the list names are
	now identical to the mark levels.

   DESCRIPTION
   NEWS
	updated.