revert: no new idiom if it can be used only at a handful of occasions.

rather, I would need Ruby's each_with_index.

pub/src/mem.cpp

@@ -78,8 +78,8 @@ namespace NOlm {
     //! Step up or down.
     void sel_increment( int step )
     {
-        for( int& k: FSel.V )
-            k += step;
+        for( int i=0; i<FSel.size(); ++i )
+            FSel.V[i] += step;
     }
 
     //! Selected file numbers as string.
@@ -100,8 +100,8 @@ namespace NOlm {
     int nJ_max()
     {
         int ret = 0;
-        for( int k: FSel.V )
-            ret = max( ret, MOM[k]->nJ() );
+        for( int i=0; i<FSel.size(); ++i )
+            ret = max( ret, MOM[FSel.V[i]]->nJ() );
         return ret;
     }
 }