Save the Tutorial

I've added a tutorial that covers the basics required for base building and navigation.  I would love to get some feedback, so far it's been pretty quiet around here.

So far a new world gets created for every game. I noticed this was not optimal for a tutorial. I don't have a world map editor, so I decided to add save/load functionality. This allowed me to chose one of the random generated tutorials and save it. So every time the tutorial is started, it's now started from the same save file.

The save/load functionality is also applied to the main game. So in theory you can stop and restart at any time, as long as you use the same browser and not the incognito tab.