unify header popup menus toggle behaviour
remove old toggle script
simplify css
Merge remote-tracking branch 'origin/master' into top-nav-improvements
Merge remote-tracking branch 'origin/master' into top-nav-improvements

Conflicts:
	common/app/assets/stylesheets/layout/_header.scss
	common/app/views/fragments/topNav/servicesLinks.scala.html
make more link target services menu
css adjustments
add style for links states
Merge remote-tracking branch 'origin/master' into top-nav-improvements
don't allow link text to be selected
remove opera user select
Merge pull request #5124 from guardian/top-nav-improvements

Top navigation improvements