update middleman dependencies to 3.2.0
moved files
changed comment
update normalize and defaults with new mixins
new variables, $font-icon, $webfont
removed em() function
new clearfix and ir placeholder mixin
changed folders
ignore Gemfile.lock
new functions & mixins: flexbox, font, icon, rgba-fallback mixin, measure-margin & match function,
add Modernizr 2.7.1, remove Modernizr 2.6.2