Delete redisplay-end-trigger-functions and related defuns
This variable and related functions have been obsolete since 23.1.
The last things to depend on this (fast-lock.el and lazy-lock.el) were
recently removed.
* src/dispextern.h (struct it): Delete field
'redisplay_end_trigger_charpos'.
* src/window.c (Fwindow_redisplay_end_trigger)
(Fset_window_redisplay_end_trigger): Delete defuns and corresponding
defsubrs for functions obsolete since 23.1.
* src/window.h (wset_redisplay_end_trigger): Delete function.
(GCALIGNED_STRUCT): Delete 'redisplay_end_trigger'.
* src/xdisp.c (run_redisplay_end_trigger_hook): Delete function.
(syms_of_xdisp) <redisplay_end_trigger_functions>: Delete
variable obsolete since 23.1.
(init_iterator, next_element_from_buffer): Don't run or set above
deleted hook variable.