[fb] Support dfs.umaskmode, fs.permissions.umask-mode when creating files or folders

When creating files/folders in the FileBrowser, Hue does not honor fs.permissions.umask-mode. Harsh mentioned this is because the WebHDFS API does not read the fs.permissions.umask-mode property, instead it uses whatever value is explicitly passed by Hue or the NN default. Can we add a umask property tot he filebrowser for Hue to handle this?