Added Markdown editor and Javascript code refactoring

assets/js/src/ProjectPermission.js

@@ -0,0 +1,19 @@
+Kanboard.ProjectPermission = function(app) {
+    this.app = app;
+};
+
+Kanboard.ProjectPermission.prototype.listen = function() {
+    $('.project-change-role').on('change', function () {
+        $.ajax({
+            cache: false,
+            url: $(this).data('url'),
+            contentType: "application/json",
+            type: "POST",
+            processData: false,
+            data: JSON.stringify({
+                "id": $(this).data('id'),
+                "role": $(this).val()
+            })
+        });
+    });
+};