3.1.0: Mega Navigation and Tools Support

• Replaces grunt-contrib-sass with grunt-sass (uses node-sass under the hood)
• Uses full path to node modules depenencies, rather than depending on loadPath
• Small bugfixes when trying to compile sass locally in this repo, due to
  incorrect paths.
• Add a new partial, burf-tools, for minimal uses of Foundation
• Adds mega menu support for child themes by default.
• Fixes an issue preventing the icons mixin from being used inside media queries
• Icon placeholders and classes are now generated from the $icons-responsive map
• Adds the ability to change the before/after placement of icons globally across
  the theme
• Fixes skip link issues #173
• Fixes a spacing issue with hidden page titles #174
• Adds variable to control gallery margin #174
• Fixes #103
• Fixes #97 with new $padding-banner and $padding-banner-window-width variables
• Fixes #84