Fix problems processing polyhedron connectivity.

Several filters incorrectly process polyhedra because of
misunderstandings of how their connectivity is stored or
simple math errors in computing connectivity offsets.
Fix them.

Change-Id: Icce8becea56567b869277d0d265e3f9092b7eb98
Don't forget to copy polyhedron cell-data...

... when appending datasets.

Also, clear out point-list when GetFaceStream fails.

Change-Id: Icf502a95ec8bfacc634291c6ef749d3cbdff5df9
Fix polyhedron-ray intersection...

... by properly resizing point and point-id arrays for
each polygonal face before intersecting with the ray.

Change-Id: I24b7053428e50152c8e10fcb240a56a924e772ce
Reset point ID list when appending polyhedra.

Change-Id: I0d5ef2af0323e57ef08de64235a34f4672f3bb9f
Terminate early when possible.

Change-Id: Ibcd1bb931c4f72960a3c997bf4d84653516d70f4
Merge topic '14188_polyhedron_fixes' into master

0627519c Terminate early when possible.
fc0ee6cf Reset point ID list when appending polyhedra.
ee3a7c30 Fix polyhedron-ray intersection...
31d834a4 Don't forget to copy polyhedron cell-data...
2f4a9cad Fix problems processing polyhedron connectivity.