tree->position rearranged for clarity.
* intervals.c (find_interval): Consistently treat POSITION as an
actual buffer position, i.e. origin 1. The old code seemed
undecided on this point. Treat the end of the buffer as being
part of the rightmost interval.
(adjust_intervals_for_insertion): Consistently treat POSITION as
origin 1.
(interval_deletion_adjustment): The exception: FROM should be
origin zero here. Consistently treat it as such. Simplify code
which shrinks and possibly deletes intervals.
(adjust_intervals_for_deletion): Treat start as origin 1; our
caller does.
(set_point): Use buffer positions throughout, not a mix of buffer
posns and origin zero posns.
(get_local_map): Remove special case for POSITION at end of buffer;
find_interval handles that case correctly.
(verify_interval_modification): Remove special case for START at
end of buffer.
* textprop.c (validate_interval_range): End-of-buffer/string
positions no longer need special handling.
* intervals.c (make_new_interval): #if 0 this out. Nobody calls it.
specially. For non-insertions, check only the chars being changed.
`modification-hooks' property is now a list of functions.
(set_point): Ignore chars outside current restriction.
(set_point): Considerable rewrite. Handle intervals both
before and after the old and new point values.
Redo handling of invisible intervals, and of motion hooks.
(textget): New function.
(graft_intervals_into_buffer):
create_root_interval needs Lisp object arg.
Set tree to new root interval.
Don't test TREE_LENGTH if buffer has no intervals.
Rearrange code to copy properties so that it really
does merge the inserted ones into the inherited ones.
(traverse_intervals): Pass `arg' on recursive calls.
(split_interval_left): Use new_length as basis for length of new.
(traverse_intervals): New arg ARG.
