I have attached the new files and all modifications done by Mihaela to
include the new shape TGeoXtru representing the old TXTRU shape.
Currently she implemented the Contains() method. The shape can be also
visualized in the pad or x3d (see atached macro). The only limitation in
x3d is that the end-polygons are not decomposed into convex polygons, so
in case the section of the TGeoXtru is concave the drawing is not well
handled.
  I also included a minor modification in TGeoManager.h needed by FLUKA
(that now can perform tracking and completers gAlice->Run() with TGeo!!!)


git-svn-id: http://root.cern.ch/svn/root/trunk@8163 27541ba8-7e3a-0410-8455-c3a389f83636