Commit JT 072619

- added a min_style option for norm type (euclidean or Max)
- adapted and tested spin minimizers
- adapted (net tested) regular minimizers

src/min_sd.cpp

@@ -79,7 +79,8 @@ int MinSD::iterate(int maxiter)
 
     // force tolerance criterion
 
-    fdotf = fnorm_sqr();
+    if (normstyle == 1) fdotf = fnorm_inf();	// max force norm
+    else fdotf = fnorm_sqr();			// Euclidean force norm
     if (fdotf < update->ftol*update->ftol) return FTOL;
 
     // set new search direction h to f = -Grad(x)