[#50928529] fixed mobile header button.  reorganized header code into a separate files.
[#50928529] added enquire.js and removed davis.js and state-machine.js which are no longer used.
[#50928529] header hiding/showing properly on mobile or desktop in all cases.
[#50928529] fixed the menu behaviour to disappear when clicking a button and clicking outside the menu.
[#50928475] added a timer to prevent problems when clicking too fast on the header.
[#50928529] refined behavior of menu
[#50929107] merged responsive branch into steve branch