stop votes details link being pushed to next line

by setting right padding on the li and a negative right margin on the
link we make sure there is enough room for it and it's still up against
the right edge of the line. Otherwise it can cause long lines to be
reformatted or be pushed down to the next line on narrow screens
add side margin to header on mobile

stops it pressing up against the edge of the screen
slightly narrower action buttons on mobile

keeps them on the same line rather than splitting over two
put everthing in the footer in 1 column on mobile

not sure this is quite what we want but it's much better than it all
being squashed in
Merge remote-tracking branch 'origin/mp-page-template' into mp-page-template