Add option to not show MathPlayer alert (helps with testsuite)

unpacked/jax/output/NativeMML/jax.js

@@ -195,6 +195,7 @@
           //
           //  If that fails, give an alert about security settings
           //
+          if (!this.config.noMathPlayerWarning) {
 	    alert(MathJax.Localization._(["MathML", "MathPlayer"],
 	          "MathJax was not able to set up MathPlayer.\n\n"+
 	          "If MathPlayer is not installed, you need to install it first.\n"+
@@ -207,6 +208,7 @@
 	          "Currently you will see error messages rather than\n"+
 	          "typeset mathematics."));
           }
+        }
       } else {
         //
         //  Get the default sizes (need styles in place to do this)