Disable save button once clicked

Done via CSS `pointer-events`, now supported by all major browsers, to
avoid messing with the form's js processing

themes/grav/app/pages/page/disable-buttons.js

@@ -0,0 +1,5 @@
+import $ from 'jquery';
+
+$('button[value="save"]').on('click', function() {
+    $(this).addClass('pointer-events-disabled');
+});

themes/grav/app/pages/page/index.js

@@ -2,6 +2,7 @@ import $ from 'jquery';
 import './add';
 import './move';
 import './delete';
+import './disable-buttons';
 import './media';
 import './multilang';
 

themes/grav/css-compiled/fonts.css

@@ -1,3 +1 @@
 @import url("//fonts.googleapis.com/css?family=Montserrat:400|Lato:300,400,700|Inconsolata:400,700");body,h5,h6,.badge,.note,.grav-mdeditor-preview,input,select,textarea,button,.selectize-input{font-family:"Lato","Helvetica","Tahoma","Geneva","Arial",sans-serif}h1,h2,h3,h4,#admin-menu li,.form-tabs>label,.label{font-family:"Montserrat","Helvetica","Tahoma","Geneva","Arial",sans-serif}code,kbd,pre,samp,body .CodeMirror{font-family:"Inconsolata","Monaco","Consolas","Lucida Console",monospace !important}
-
-/*# sourceMappingURL=fonts.css.map */

themes/grav/css-compiled/simple-fonts.css

@@ -1,3 +1 @@
 body,h5,h6,.badge,.note,.grav-mdeditor-preview,input,select,textarea,button,.selectize-input,h1,h2,h3,h4,#admin-menu li,.form-tabs>label,.label{font-family:"Helvetica Neue", "Helvetica", "Tahoma", "Geneva", "Arial", sans-serif}code,kbd,pre,samp,body .CodeMirror{font-family:"Monaco", "Consolas", "Lucida Console", monospace}
-
-/*# sourceMappingURL=simple-fonts.css.map */

themes/grav/scss/template/_admin.scss

@@ -952,4 +952,8 @@ body.sidebar-quickopen #admin-main {
             line-height: 20px;
         }
     }
+}
+
+.pointer-events-disabled {
+    pointer-events: none;
 }