Add ability to share programs

[raxod502]

It would be nice if it were possible to click a button and get a link that would show someone else the same code that you had written. Two options:

• server-side persistent database with link shortening functionality hooked up to it
• fully client-side where the program text is base64 encoded or similar

[jinnovation]

This would be super useful and unlock one of the IMO most useful aspects of the Go Playground.