CON-1448 | GlobalHeader grid column size calculation
CON-1448 | Global Nav column width mixin 2nd round
CON-1448 | CNW button on breakpoints
CON-Venus | added grid calculation functions (developed for CON-VenusSearchPage)

Conflicts:
	extensions/wikia/Venus/styles/layout.scss
	extensions/wikia/Venus/styles/variables.scss
New search input for global nav
CON-1445 fix chevron colors