Save level2

[piotrgajcy]

Save and update level data

[stared]

@piotrgajcy I tried, but don't nearly understand.

• I click save, and nothing happens.
• There is no view with a list of all saved levels. (So, I don't know how to load.)

In general, I expect it to be saving board (NOT associated with say, "level 5"). And even it if is from, say, level 5 - then to be it as if it were created from a sandbox, or anything else.

[stared]

Closes, as I already merged a fresher one, #88.