Require ImageMagick >= 6.3.5, due to PixelSetMagickColor.

* configure.ac (IMAGEMAGICK_MODULE): Bump prereq from 6.2.8 to 6.3.5.
A more-complicated fix would be to remove uses of PixelSetMagickColor,
introduced in ImageMagick 6.3.5 (Sept. 2007).

Fixes: debbugs:17339

ChangeLog

+2014-05-03  Paul Eggert  <eggert@cs.ucla.edu>
+
+	Require ImageMagick >= 6.3.5, due to PixelSetMagickColor (Bug#17339).
+	* configure.ac (IMAGEMAGICK_MODULE): Bump prereq from 6.2.8 to 6.3.5.
+	A more-complicated fix would be to remove uses of PixelSetMagickColor,
+	introduced in ImageMagick 6.3.5 (Sept. 2007).
+
 2014-05-02  Paul Eggert  <eggert@cs.ucla.edu>
 
 	Consult libpng-config more consistently (Bug#17339).

configure.ac

@@ -2225,11 +2225,9 @@ fi
 HAVE_IMAGEMAGICK=no
 if test "${HAVE_X11}" = "yes" || test "${HAVE_NS}" = "yes" || test "${HAVE_W32}" = "yes"; then
   if test "${with_imagemagick}" != "no"; then
-    ## 6.2.8 is the earliest version known to work, but earlier versions
-    ## might work - let us know if you find one.
-    ## 6.0.7 does not work.  See bug#7955.
+    ## 6.3.5 is the earliest version known to work; see Bug#17339.
     ## 6.8.2 makes Emacs crash; see Bug#13867.
-    IMAGEMAGICK_MODULE="Wand >= 6.2.8 Wand != 6.8.2"
+    IMAGEMAGICK_MODULE="Wand >= 6.3.5 Wand != 6.8.2"
     PKG_CHECK_MODULES(IMAGEMAGICK, $IMAGEMAGICK_MODULE, HAVE_IMAGEMAGICK=yes, :)
     AC_SUBST(IMAGEMAGICK_CFLAGS)
     AC_SUBST(IMAGEMAGICK_LIBS)