searchableSurface: Renamed geometry directory triSurface -> geometry

Originally the only supported geometry specification were triangulated surfaces,
hence the name of the directory: constant/triSurface, however now that other
surface specifications are supported and provided it is much more logical that
the directory is named accordingly: constant/geometry.  All tutorial and
template cases have been updated.

Note that backward compatibility is provided such that if the constant/geometry
directory does not exist but constant/triSurface does then the geometry files
are read from there.

tutorials/mesh/snappyHexMesh/pipe/Allclean

@@ -5,7 +5,7 @@ cd ${0%/*} || exit 1    # Run from this directory
 . $WM_PROJECT_DIR/bin/tools/CleanFunctions
 
 # Remove surface
-rm -rf constant/triSurface
+rm -rf constant/geometry
 
 rm -rf constant/extendedFeatureEdgeMesh
 

tutorials/mesh/snappyHexMesh/pipe/Allrun

@@ -5,8 +5,8 @@ cd ${0%/*} || exit 1    # Run from this directory
 . $WM_PROJECT_DIR/bin/tools/RunFunctions
 
 # Copy pipe surface from resources directory
-mkdir -p constant/triSurface
-cp $FOAM_TUTORIALS/resources/geometry/pipe*.obj.gz constant/triSurface/
+mkdir -p constant/geometry
+cp $FOAM_TUTORIALS/resources/geometry/pipe*.obj.gz constant/geometry/
 
 runApplication surfaceFeatures
 runApplication blockMesh