Retrospective commit from 2009-09-12.

Retrospective commit from 2009-09-12.

Undo changes from 2009-09-11.  Set row->end and row->start in
xdisp.c:display_line.

 dispnew.c (direct_output_for_insert): Give up if we are
 reordering bidirectional text.
 dispextern.h (IT_STACK_SIZE): Enlarge to 5.
 xdisp.c (display_line): Set row->end and it->start for the next
 row to the next character in logical order.  If we are reordering
 bidi text, push and pop the iterator before and after momentarily
 iterating in logical order.