Merge branch 'menu-update' with zoom-update (disables discoverability for now)

unpacked/MathJax.js

@@ -1202,7 +1202,7 @@ MathJax.Hub = {
       ALT: false,          //    require Alt or Option?
       CMD: false,          //    require CMD?
       Shift: false,        //    require Shift?
-      discoverable: true,  //  make math menu discoverable on hover?
+      discoverable: false, //  make math menu discoverable on hover?
       zscale: "200%",      //  the scaling factor for MathZoom
       renderer: "",        //  set when Jax are loaded
       font: "Auto",        //  what font HTML-CSS should use

unpacked/extensions/MathMenu.js

@@ -845,8 +845,8 @@
           ITEM.RADIO("Browser", "context")
         ),
         ITEM.COMMAND("Scale All Math ...",MENU.Scale),
-        ITEM.RULE(),
-        ITEM.CHECKBOX("Highlight on Hover", "discoverable")
+        ITEM.RULE().With({hidden: true}),
+        ITEM.CHECKBOX("Highlight on Hover", "discoverable", {hidden: true})
       ),
       ITEM.RULE(),
       ITEM.COMMAND("About MathJax",MENU.About),