iMesh instance (moab) and a "model root" set
this function is a special brand, it makes a direct connection between
iMesh and iGeom; right now, it can't be easily declared
in FBiGeom.h, because it has the iMesh_Instance as input parameter. 
The implementation of this new function (FBiGeom_newGeomFromMesh) is in
FBiGeom_MOAB.cpp, but its declaration should be maybe somewhere else 
(for the example to run, I just declared it extern in the test itself :( )



git-svn-id: https://svn.mcs.anl.gov/repos/ITAPS/MOAB/trunk@5261 6162379e-bd28-0410-9a7d-b7f4dcfcad3c