lnodes: added degree < 0 to handle lower-dimensional continuity
added p4est_ghost_support_nodes()

ghost: p4est_ghost_support_nodes() compiles

fixes to p4est_ghost_support_nodes()

limit test of support_nodes() to 2 procs for now
added checksums to p4est_ghost_is_valid()

fixes to p4est_ghost_is_valid()
move p4est_ghost_support_nodes() to p4est_ghost_support_lnodes()

clean up p4est_ghost_support_lnodes
added p4est_ghost_expand_by_lnodes()
lnodes: fix c++ compile
start p4est_plex
saving progress on p4est_plex
compiles
plex is almost done
added p8est_plex.c
plex: put in p4est_to_plex transforms
plex: added .h files
added petsc config option
plex: orientation fix to match petsc
plex: start test_plex
plex: test clean, 2d, 1 proc, no refinement
plex: compute coordinates
plex: test_plex runs, 3d, serial
plex: first attempt at comparing vtk: still bugs