Bug or missing feature: Prevent font-lock from changing text
properties on text that has property `font-lock-ignore'.  See
http://lists.gnu.org/archive/html/emacs-devel/2014-08/msg00540.html

Patch attached.  ChangeLog entry:

2014-08-30 Drew Adams  <drew.adams@oracle.com>
	* font-lock.el: Respect text property `font-lock-ignore'.
        (put-text-property-unless-ignore): New function.
	(font-lock-default-unfontify-region): Do not unfontify if
	text has property `font-lock-ignore'.
	(font-lock-prepend-text-property, font-lock-append-text-property)
	(font-lock-fillin-text-property, font-lock-apply-syntactic-highlight)
	(font-lock-fontify-syntactically-region, font-lock-apply-highlight)
	(font-lock-fontify-anchored-keywords)
	(font-lock-fontify-keywords-region):
        Use put-text-property-unless-ignore, not put-text-property.

In GNU Emacs 24.4.50.1 (i686-pc-mingw32)
 of 2014-08-15 on LEG570
Bzr revision: 117706 rgm@gnu.org-20140815043406-p5hbu97cbm7pulcn
Windowing system distributor `Microsoft Corp.', version 6.1.7601
Configured using:
 `configure --enable-checking 'CFLAGS=-O0 -g3' CPPFLAGS=-DGLYPH_DEBUG=1'