ICON't believe it's not butter

Added

• Hollow version of Buildit logo
• Github icon
• SVG symbols now have IDs on their <title> elements
• New utility class grav-u-max-word-count-m. Useful to limit p max width for better readability

Changed

• Buildit logo has been updated to new design
• Inline SVG component now uses aria-labelledby to reference SVG symbol's title
• Updated favicon.ico to new Buildit icon.
• BREAKING: Renamed social media SVG IDs to icon-*
• Inverted font-weight on block-link, now bold is used for the active link

Fixed

• Toggle buttons (incl. hamburger menu button) now work in IE11
• Header now has normal height in IE11 on small screens
• SVG validation errors