Update colormap files with faster code. * autumn.m, bone.m, cool.m, copper.m, flag.m, gmap40.m, gray.m, hot.m, hsv.m, jet.m, lines.m, ocean.m, pink.m, prism.m, rainbow.m, spring.m, summer.m, white.m, winter.m: Use indexing in place of kron or repmat for faster code.

--- a/scripts/image/spring.m
+++ b/scripts/image/spring.m
@@ -43,7 +43,7 @@
     map = [1, 0, 1];
   elseif (n > 1)
     r = ones (n, 1);
-    g = (0:n - 1)' ./ (n - 1);
+    g = [0:(n-1)]' / (n - 1);
     b = 1 - g;
     map = [r, g, b];
   else