WebUI: Fix watched folders on Gecko

Passing objects to push() seems to be broken on Firefox, making the
preferences impossibile to use when there are watched folders.
Fix this by passing strings instead of elements.

src/webui/www/public/preferences_content.html

@@ -617,16 +617,10 @@ addWatchFolder = function() {
   if(new_folder.length <= 0) return;
   
   var download_here = $('new_watch_folder_dl').getProperty('checked');
-  var myinput = new Element('input');
   var i = $('watched_folders_tab').getChildren('tbody')[0].getChildren('tr').length;
-  myinput.setProperty('id', 'text_watch_'+i);
-  myinput.setProperty('type', 'text');
-  myinput.setProperty('value', new_folder);
   
-  var mycb = new Element('input');
-  mycb.setProperty('type', 'checkbox');
-  mycb.setProperty('id', 'cb_watch_'+i);
-  mycb.setProperty('checked', download_here);
+  var myinput = "<input id='text_watch_"+ i +"' type='text' value='" + new_folder + "'>";
+  var mycb = "<input id='cb_watch_"+ i +"' type='checkbox' checked='" + download_here + "'>";
   WatchedFoldersTable.push([myinput, mycb]);
   
   // Clear fields
@@ -740,14 +734,8 @@ loadPreferences = function() {
                     updateTempDirEnabled();
                     var i;
                     for(i=0; i<pref.scan_dirs.length; i+=1) {
-                      var myinput = new Element('input');
-                      myinput.setProperty('id', 'text_watch_'+i);
-                      myinput.setProperty('type', 'text');
-                      myinput.setProperty('value', pref.scan_dirs[i]);
-                      var mycb = new Element('input');
-                      mycb.setProperty('type', 'checkbox');
-                      mycb.setProperty('id', 'cb_watch_'+i);
-                      mycb.setProperty('checked', pref.download_in_scan_dirs[i]);
+                      var myinput = "<input id='text_watch_"+ i +"' type='text' value='" + pref.scan_dirs[i] + "'>";
+                      var mycb = "<input id='cb_watch_"+ i +"' type='checkbox' checked='" + pref.download_in_scan_dirs[i] + "'>";
                       WatchedFoldersTable.push([myinput, mycb]);
                     }