[release,doc] include eps-figures in grid-howto.pdf

At least on my system dvipdf had problems with the relative paths
used to specify the figures:
dvips: Could not find figure file ./EPS/fem3d.eps; continuing.
dvips: Could not find figure file ./EPS/alberta2d.eps; continuing.
dvips: Could not find figure file ./EPS/ugsimplex2d.eps; continuing.
dvips: Could not find figure file ./EPS/ugcube2d.eps; continuing.
dvips: Could not find figure file ./EPS/alberta3d.eps; continuing.
dvips: Could not find figure file ./EPS/alusimplex3d.eps; continuing.
dvips: Could not find figure file ./EPS/alucube3d.eps; continuing.
dvips: Could not find figure file ./EPS/ugsimplex3d.eps; continuing.
dvips: Could not find figure file ./EPS/ugcube3d.eps; continuing.
dvips: Could not find figure file ./EPS/iso.eps; continuing.

As the TEXTINPUTS variable is set to include the correct paths, I fixed this
by skipping ./ in the path.