update layers to remove warnings

benchmarks/extrude/tunnel_simpler.geo

 // Gmsh project created on Wed Jan 31 21:34:00 2007
+Geometry.ExtrudeReturnLateralEntities = 0;
 
 // definition of geometry
 radius = 5;

benchmarks/extrude/vianew-rec.geo

@@ -97,18 +97,13 @@ NLup = 3;
 // extrude down first:
 Extrude {0,0,-A*L} {
   Surface{42};
-  Layers { {NLdn}, {9001}, {1} } ; 
+  Layers { NLdn } ; 
   Recombine;
 }
 
 // extrude up second:
 Extrude {0,0,L} {
   Surface { 26:42:2 };
-  Layers { {NLup}, {9000}, {1} }; 
+  Layers { NLup }; 
   Recombine;
 }
-
-// wafer surface including surfaces that are extruded downwards:
-Physical Surface(1001) = {26,28,30,32,34,36,38,40, 51,55,59,63,64};
-Physical Surface(1009) = {73,95,117,121,139,161,165,183,205,209,227,85, 86,108,130,152,174,196,218,240,262};
-Physical Volume(2001)  = {9000,9001};

benchmarks/extrude/vianew.geo

@@ -95,16 +95,12 @@ NLup = 3;
 // extrude down first:
 Extrude {0,0,-A*L} {
   Surface{42};
-  Layers { {NLdn}, {9001}, {1} } ; 
+  Layers { NLdn } ; 
 }
 
 // extrude up second:
 Extrude {0,0,L} {
   Surface { 26:42:2 };
-  Layers { {NLup}, {9000}, {1} }; 
+  Layers { NLup }; 
 }
 
-// wafer surface including surfaces that are extruded downwards:
-Physical Surface(1001) = {26,28,30,32,34,36,38,40, 51,55,59,63,64};
-Physical Surface(1009) = {73,95,117,121,139,161,165,183,205,209,227,85, 86,108,130,152,174,196,218,240,262};
-Physical Volume(2001)  = {9000,9001};

doc/VERSIONS

-$Id: VERSIONS,v 1.387 2007-07-11 17:55:46 geuzaine Exp $
+$Id: VERSIONS,v 1.388 2007-07-13 14:12:07 geuzaine Exp $
 
-2.0.8 (Jul XX, 2007): unused vertices are not saved in mesh files
+2.0.8 (Jul 13, 2007): unused vertices are not saved in mesh files
 anymore; new plugin GUI; automatic GUI font size selection; renamed
 Plugin(DecomposeInSimplex) into Plugin(MakeSimplex); reintroduced
 enhanced Plugin(SphericalRaise); clarified meshing algo names; new
-option to save groups of nodes in UNV meshes; many small improvements
-and small bug fixes.
+option to save groups of nodes in UNV meshes; new background mesh
+infrastructure; many small improvements and small bug fixes.
 
 2.0.7 (Apr 3, 2007): volumes can now be defined from external CAD
 surfaces; Delaunay/Tetgen algorithm is now used by default when