Fix bug in function PIP3D where R crashes if there are some vertices in the input VERTICES argument that are not actually used in the input FACES argument. The fix is to create an internal version of the input VERTICES argument that contains ONLY vertices that are actually used in the input FACES argument. The input FACES argument also needs to be updated to reflect the reduced number of rows in the input VERTICES argument. The updated VERTICES and FACES argument can then be forwarded to the underlying C++ method.

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/ptinpoly@13 edb9625f-4e0d-4859-8d74-9fd3b1da38cb