make default $browser-supports-columns overwriteable
make $browser-supports-columns false by default if it's $old-ie
add a rudimentary fallback for css columns
restyle colophon links
update colphon links
update test to reflect case change in colophon links
make columns mixin a little more resilient
account for columns mixin change
pass relevent query strings
adjust padding
add securedrop/all topics links
show desktop site link on mobile in footer
renaming variable
removing old variable definition
Merge pull request #5697 from guardian/footer-colours

Update to footer styling