(Fset_time_zone_rule): Move static var environbuf

(Fset_time_zone_rule): Move static var environbuf
to top level.
(syms_of_editfns): Initialize environbuf explicitly.

(Vbuffer_access_fontified_property): New variable.
(syms_of_editfns): Set up Lisp var.
(make_buffer_string): Don't call the Vbuffer_access_fontify_functions
if the text is already fontified.
(Fbuffer_string): Pas 1 for PROPS arg.
(update_buffer_properties): New subroutine.
(Finsert_buffer_substring): Use update_buffer_properties.

(make_buffer_string): New arg PROPS.
(Fbuffer_string, Fbuffer_substring): Pass new arg.
(Fbuffer_substring_no_properties): New function.
(syms_of_editfns): defsubr it.
(Vbuffer_access_fontify_functions): New variable.
(Qbuffer_access_fontify_functions): New variable.
(syms_of_editfns): Set up Lisp variable, initialize them.
(make_buffer_string): Run this new hook.