Tiny.cc service restored - all links in labs working again

Tiny.cc is back up again so all the links appearing in the instructions (Lab 1b, Steps 5 & 23) and Lab 2b (Step 6) are working again. Tiny.cc is normally reliable, but in the event that it goes down again someday, the direct links are now readily available to students in the Help FAQ so they will always be able carry on without too much disruption to their work.