Language Selection

Fixes #144. This adds a language selection dropdown to the footer which allows the user to change their language which will result in changing the site content. This will also make it clear that #160 is not an issue.
I didn't have any issue with it firing with Chromium but I'll poke at it again. I suppose there is no major harm in triggering on blur though it may fire when it isn't needed, namely when it loses focus but wasn't actually changed.