Fix display of Hebrew tutorial title on splash screen.

Fix display of Hebrew tutorial title on splash screen.

 lisp/startup.el (fancy-startup-text): Read the whole tutorial, not
 just its first 256 bytes.  Prevents gibberish in display of the
 tutorial title.
 etc/tutorials/TUTORIAL.he: Make the first sentence display correctly
 in a left-to-right paragraph, such as what is shown on the fancy
 splash screen, by using directional control characters.