Refs #2283: show hamburger menu on 800px and beyond
Refs #2283: move hamburger menu to left
Refs #2283: custom colours for hamburger menu
Refs #2283: custom colours for accordion global menu for ASCOBANS
Refs #2283: custom colours for accordion global menu, for all themes
Refs #2275: arrange search box on 800, 600, 480px mobile resolutions
Merge pull request #167 from sandriu/master

arrange global menu and search on mobiles