When a tileset object is available on the server but it has not been generate (file_size attrib wont exist), the tileset should be listed in the list of them form the server but should be grayed out in the same manner that read only layers are grayed out.
When a tileset object is available on the server but it has not been generate (file_size attrib wont exist), the tileset should be listed in the list of them form the server but should be grayed out in the same manner that read only layers are grayed out.