ENH/BUG: featureEdgeMesh/conformalVoronoiMesh.

No longer reading or writing edgeDirections - calculating them on
read.

Properly initialising data in featureEdgeMesh constructor.

Fixing use of extend for treeBoundBox.

Removing writeObj from featureEdgeMesh constructor - calling
explicitly from surfaceFeatureExtract.

applications/utilities/surface/surfaceFeatureExtract/surfaceFeatureExtract.C

@@ -278,10 +278,11 @@ int main(int argc, char *argv[])
     (
         newSet,
         runTime,
-        surfFileName.lessExt().name() + ".feMesh",
-        true
+        surfFileName.lessExt().name() + ".featureEdgeMesh"
     );
 
+    feMesh.writeObj(surfFileName.lessExt().name());
+
     feMesh.write();
 
     Info<< "End\n" << endl;