updated DebugSwitches, surfaceWriter

- added obj surfaceWriter
- don't bother with prepended field names on obj and stl surfaceWriter.
  It fills the disk and suggests differences where there are none.

tutorials/electromagnetics/mhdFoam/hartmann/system/sampleDict

@@ -19,9 +19,19 @@ interpolationScheme cellPoint;
 
 setFormat       raw;
 
-sets            ( line_centreProfile { type uniform ; axis distance ; start ( 10.001 -1 0.01 ) ; end ( 10.001 1 0.01 ) ; nPoints 100 ; } );
+sets
+(
+    line_centreProfile
+    {
+        type    uniform;
+        axis    distance;
+        start   ( 10.001 -1 0.01 );
+        end     ( 10.001 1 0.01 );
+        nPoints 100;
+    }
+);
 
-surfaces        ( );
+surfaces        ();
 
 fields          ( Ux );