Adding Gig Linden

Although, I don't really know why.  In order to use WLAN here, you have to
create an account, whereby your mobile phone number is required, and then
you get "free" access to WLAN for 30 minutes.  You get an extra hour for
every Beck's beer you drink, which is a pity in a pub which sells specialty
beers...
Merge branch 'master' of github.com:paultcochrane/HannoverHotspots