Removed old version
Created a backup folder with original images and js scripts
Patched imagemin to output right compression rate with equal src and dest
Included patched imagemin in repo and removed dep from package.json
Added grunt-newer and grunt-contrib-clean to package.json deps

Gruntfile is a work in progress - experimented with new watch and imagemin tasks. Now yet cleaned up but grunt compress-and-watch-new-img should be functional.