landingJS: make from path in zip optional

landing.js

@@ -61,7 +61,22 @@
   }
 
   function loadZipIntoCrib(gadget, zip, from_path) {
-    var promise_list = [];
+    var promise_list = [], path_list = [], root_path = "", i;
+    zip.forEach(function (relativePath, zipEntry) {
+      path_list.push(relativePath);
+    });
+    if (path_list && path_list.length > 1) {
+      root_path = path_list[0].split("/")[0];
+      for (i = 0; i < path_list.length - 1; i++) {
+        if (root_path !== path_list[i].split("/")[0]) {
+          root_path = "";
+          break;
+        }
+      }
+    }
+    if (root_path !== "" && !from_path) {
+      from_path = root_path;
+    }
     zip.forEach(function (relativePath, zipEntry) {
       var end_url;
       if (zipEntry.dir) {
@@ -141,7 +156,7 @@
         site = getURL.protocol + "//" + getURL.host,
         params = getParameterDict(),
         data = {
-          from_path: "cribjs-editor-master/",
+          from_path: "",
           to_path: site,
           zip_url: "https://lab.nexedi.com/cedric.leninivin/cribjs-editor/" +
             "-/archive/master/cribjs-editor-master.zip",