[WIP] mobile interface

Lots of small things remain to be fixed, but most of it seems to work.
In particular, the submenu dropdown doesn't work yet on touchscreens and
most of the 'smoelenboek' has not been optimized yet.
Merge branch 'master' into mobile-layout
Merge remote-tracking branch 'khandhas/master' into mobile-layout
Do not break the Nivo Slider
Keep homepage lay-out on IE8
small margin improvements (menu, body text)
Merge branch 'static' into mobile-layout

Conflicts:
	kn/base/templates/base/bare.css
	kn/base/templates/base/base.css

Note: the CSS got (slightly) changed to fix some problems with this
merge.
Ensure the login window stays in the middle on mobile

This fixes a problem in Safari on the iPhone.
This also moves the login button and the first name to the right.
Fix ugly black border on iOS when opening the login window
Mobile-friendly menu inside Smoelenboek
Improve submenu design on small screens
Redesign 'Nieuwe activiteit' template in a mobile friendly way
Reverse the order of agenda and slider on smaller screens

Some other parts of the lay-out have changed there too.
Fix issue with /over menu on very small screens
Made the agenda more modular

Also fix some issues on the home page (I didn't want to reinvent the wheel so I
made the agenda more modular first).
Fix small issue in user detail page + mobile menu

If there was no user photo, text would be layered over the menu.
Support agenda-first on home on old Android browsers
Don't reverse the order on IE: it has a buggy flexbox implementation
Merge pull request #7 from khandhas-infra/mobile-layout

Mobile interface