Bump pages/ src path

use this only in demo/
Bump src/assets/images/

-> src/img/ only
Update package.json

add grunt-contrib-imagemin@0.1.4 in devDependencies
Update Gruntfile.js

add dist-img task with imagemin
Update Gruntfile.js

add copy:imagesToDemo task
Update Gruntfile.js

add copy in dist task
Optimize dist/img/ files

with imagemin grunt task
Update Gruntfile.js

bump copy:fonts~ task
Bump dist/fonts/

-> dist/font/ with no fontfile at moment
Clean demo/assets/font path
Update demo/assets/css/style.css

use Helvetica Neue as font-family -> topcoat heavy font pack
Dist demo/assets/img files

optimized with imagemin