compress and interlace all image assets

[00:20:25] gulp-image-optimization: ✔ img/favicon/favicon.png (saved 6.3 kB)
[00:20:25] gulp-image-optimization: ✔ img/favicon/favicon2.png (saved 74 B)
[00:20:25] gulp-image-optimization: ✔ img/favicon/favicon2_nbg.png (saved 40 B)
[00:20:25] gulp-image-optimization: ✔ img/favicon/favicon3.png (saved 16 B)
[00:20:25] gulp-image-optimization: ✔ img/favicon/favicon3_nbg.png (already optimized)
[00:20:25] gulp-image-optimization: ✔ img/favicon/ghost.png (saved 37 B)
[00:20:25] gulp-image-optimization: ✔ img/favicon/robot.png (saved 95 B)
[00:20:25] gulp-image-optimization: ✔ img/stars-bg.png (saved 10.6 kB)
[00:20:25] gulp-image-optimization: ✔ img/favicon/favicon1_nbg.png (saved 3.1 kB)
[00:20:25] gulp-image-optimization: ✔ img/binary.png (already optimized)
[00:20:26] gulp-image-optimization: ✔ img/stars-3.png (saved 2.7 kB)
[00:20:27] gulp-image-optimization: ✔ img/stars-1.png (saved 879 B)
[00:20:27] gulp-image-optimization: ✔ img/noise.png (saved 66 B)
[00:20:28] gulp-image-optimization: ✔ img/sonar/sonar_code_coverage.png (saved 14.8 kB)
[00:20:29] gulp-image-optimization: ✔ img/favicon/favicon1.png (saved 12.7 kB)
[00:20:29] gulp-image-optimization: ✔ img/yworks/uml.png (saved 11.8 kB)
[00:20:30] gulp-image-optimization: ✔ img/sonar/sonar_uml.png (saved 10.3 kB)
[00:20:30] gulp-image-optimization: ✔ themes/lightbright/bootstrap/img/glyphicons-halflings-white.png (already optimized)
[00:20:31] gulp-image-optimization: ✔ themes/lightbright/bootstrap/img/glyphicons-halflings.png (saved 72 B)
[00:20:31] gulp-image-optimization: ✔ img/design2.5.png (saved 32.6 kB)
[00:20:31] gulp-image-optimization: ✔ img/blog.jpg (saved 2.4 kB)
[00:20:31] gulp-image-optimization: ✔ img/blog1.5.jpg (saved 5.8 kB)
[00:20:31] gulp-image-optimization: ✔ img/blog2.jpg (saved 5.3 kB)
[00:20:31] gulp-image-optimization: ✔ img/color.jpg (saved 7.4 kB)
[00:20:31] gulp-image-optimization: ✔ img/color_large.jpg (saved 5.4 kB)
[00:20:31] gulp-image-optimization: ✔ img/foodtime.jpg (already optimized)
[00:20:31] gulp-image-optimization: ✔ img/foodwall.jpg (saved 24.4 kB)
[00:20:31] gulp-image-optimization: ✔ img/foodwall_1.0_900.jpg (saved 45.2 kB)
[00:20:31] gulp-image-optimization: ✔ img/foodwall_detail.jpg (saved 2.5 kB)
[00:20:31] gulp-image-optimization: ✔ img/fraudwatch_ipad.jpg (saved 26.1 kB)
[00:20:31] gulp-image-optimization: ✔ img/play/play_chat1.jpg (saved 5.0 kB)
[00:20:31] gulp-image-optimization: ✔ themes/twitter/bootstrap/img/glyphicons-halflings-white.png (already optimized)
[00:20:31] gulp-image-optimization: ✔ img/play/play_db1.jpg (saved 9.7 kB)
[00:20:31] gulp-image-optimization: ✔ img/play/play_helloworld.jpg (saved 5.7 kB)
[00:20:31] gulp-image-optimization: ✔ img/play/play_zentasks1.jpg (saved 4.5 kB)
[00:20:31] gulp-image-optimization: ✔ img/play/play_zentasks2.jpg (saved 4.9 kB)
[00:20:31] gulp-image-optimization: ✔ img/wallpaper/adrift.jpg (saved 24.3 kB)
[00:20:32] gulp-image-optimization: ✔ themes/twitter/bootstrap/img/glyphicons-halflings.png (saved 72 B)
[00:20:32] gulp-image-optimization: ✔ img/wallpaper/292605.jpg (saved 103.5 kB)
[00:20:32] gulp-image-optimization: ✔ img/iphone.png (saved 5.0 kB)
[00:20:34] gulp-image-optimization: ✔ img/sonar/sonar_screen.png (saved 53.0 kB)
[00:20:36] gulp-image-optimization: ✔ img/metrics/top_june10_july10_2014.png (saved 76.0 kB)
[00:20:38] gulp-image-optimization: ✔ img/metrics/june10_july10_2014.png (saved 99.1 kB)
[00:20:38] gulp-image-optimization: ✔ img/metrics/seo_june10_july10_2014.png (saved 94.8 kB)
[00:20:40] gulp-image-optimization: ✔ img/metrics/referrals_june10_july10_2014.png (saved 104.5 kB)