Added ability to navigate through context menu using keyboard keys.
Fixed menu positioning when page is scrolled
Enhanced keyboard navigation in contextMenu. Disabled items are now skipped during navigation. Enhanced code readability.
Tests for context menu keyboard navigation
Removed style for :hover on context menu item.
Removed TODO.
Merge branch 'feature/contextMenuKeyboardNav' into develop
fix context menu in IE8-10, use fast DOM methods
fix lint errors