Merge remote-tracking branch 'shashankmehta/master'

* shashankmehta/master:
  [Fix] Include the after_footer.html in the default layout
  Added support for behance.net on left sidebar
  Added support for instagram on sidebar
  Adds support for quora in leftbar. Closes #55
  Adds support for custom font through custom/fonts
  Fixes some font size issues
  Changes font to Nunito and fixes design of leftbar
  Fixes all import issues
  Fix Rake generate Invalid CSS after "@import " on _greyshade.scss Enable default custom fonts refer #https://github.com/shashankmehta/greyshade/issues/59
  changed max-width of css3 switch for better looking in new ipad (or later). When max-width is 700px, the navigtion area is in the left side of screen and very narrow. Changing max-width to 830px , as i tried, which is best suitable, could make navigation area in the upper of the screen in new ipad (or later).
  added custom/_cont.scss file
  modify sass/_greyshades.scss font-family to support customed font-family
  Updated Readme
  Allow changing of sidebar initial opacity
  Allow changing of sidebar background color

Conflicts:
    README.md
    sass/_greyshade.scss
    sass/base/_color.scss
    sass/custom/_colors.scss
    sass/screen.scss
    source/_includes/head.html
    source/_includes/header.html
    source/_layouts/default.html