Add option to skip minification of images.

@@ -522,7 +522,12 @@ module.exports = function (grunt) {
             }
             buildList.push('copy:css');         // css
             if (mpConfig.images) {
-                buildList.push('imagemin');         // image
+                var minify = mpConfig.images.options.minify;
+                if (minify === undefined || minify) {
+                    buildList.push('imagemin');         // image
+                } else {
+                    buildList.push('copy:img');         // image
+                }
                 buildList.push('svgmin');           // image
                 if (mpConfig.useRev) {
                     buildList.push('rev:img');          // image