polyself bit (trunk only)

polyself bit (trunk only)

     Some recent code shuffling introduced an unintended change in behavior
(not observable to the player; just unnecessary deletion and re-creation of
light source with identical radius when polymorphing from one light emitting
form to another).  The fixup for light range 1 would need to be repeated for
`old_light' when outside the `if (old_light != new_light)' block; move it
back inside where that isn't required.  Also, youmonst.data is valid all the
time so a couple of `Upolyd' tests in the surrounding code can be dropped.