Share and load huge game history

[yvolk]

In #4 we investigated a problem with sharing and loading games having about 50000 moves, and the app was optimized for that.
But some days ago one of my users sent me game history having 120713 moves. In order to allow sharing and loading such a huge history we need to switch completely from using one long string to saving and loading a game by chunks e.g. line by line from a file.

[yvolk]

Now we Load and Share Game as Sequence of strings, not as a single text string to minimize memory usage. Successfully tested with a game having 120 thousand moves.

Implemented in v.1.12.0, see #1