import: Replace the allowAnyoneToImport check with userCanModify

This reduces the number of hoops a user or tool must jump through to
import.

src/static/css/pad.css

@@ -71,7 +71,3 @@ input {
 @media (max-width: 800px) {
   .hide-for-mobile { display: none; }
 }
-
-#importmessagepermission {
-  display: none;
-}

src/static/js/collab_client.js

@@ -312,16 +312,6 @@ function getCollabClient(ace2editor, serverVars, initialUserInfo, options, _pad)
     }
     else if (msg.type == "ACCEPT_COMMIT")
     {
-      /*
-       * this is the first time this user contributed to this pad. Let's record
-       * it, because it will be used for allowing import.
-       *
-       * TODO: here, we are changing this variable on the client side only. The
-       *       server has all the informations to make the same deduction, and
-       *       broadcast to the client.
-       */
-      clientVars.thisUserHasEditedThisPad = true;
-
       var newRev = msg.newRev;
       if (msgQueue.length > 0)
       {

src/static/js/pad_editbar.js

@@ -415,17 +415,6 @@ var padeditbar = (function()
 
     toolbar.registerCommand("import_export", function () {
       toolbar.toggleDropDown("import_export", function(){
-
-        if (clientVars.thisUserHasEditedThisPad || clientVars.allowAnyoneToImport) {
-          // the user has edited this pad historically or in this session
-          $('#importform').show();
-          $('#importmessagepermission').hide();
-        } else {
-          // this is the first time this user visits this pad
-          $('#importform').hide();
-          $('#importmessagepermission').show();
-        }
-
         // If Import file input exists then focus on it..
         if($('#importfileinput').length !== 0){
           setTimeout(function(){