Minor zone.el fixes for bug#6483.

Minor zone.el fixes for bug#6483.
Zone did not like the intangible newlines etc in the gomoku buffer.

* lisp/play/zone.el (top-level): Do not require timer, tabify, or cl.
(zone-shift-left): Ignore intangibility, and any errors from forward-char.
(zone-shift-right): Remove no-op end-of-line.  Ignore intangibility.
(zone-pgm-putz-with-case): Use upcase-region rather than inserting,
deleting, and copying text properties.
(zone-line-specs, zone-pgm-stress): Check forward-line exit status.
(zone-pgm-rotate): Handle odd buffers like that of gomoku, where getting
to point-max is hard.
(zone-fret, zone-fill-out-screen): Replace cl's do with dotimes.
(zone-fill-out-screen): Ignore intangibility.