Set the current game mode to whatever a save file was made in when loading.

[ZayadNimrod]

Closes #747 .

Does so by squashing wizard mode and easy mode into an enumeration that is stored in the save file, and checking that this flag matches the current mode.

This will break save files, so this branch as based on master.

[ZayadNimrod]

Is this worth adding to the log in changes/?

[tmewett]

Nice, thanks, looks like the most sensible solution

There's a slight variation that's possible where we just set the mode to whatever the file says, and don't error out, if you were interested.

My only feedback is one question

[tmewett]

Is this worth adding to the log in changes/?

we usually want every user-facing change, so yes please

[ZayadNimrod]

There's a slight variation that's possible where we just set the mode to whatever the file says, and don't error out, if you were interested.

Actually now you say this I think I will change the solution.

[ZayadNimrod]

OK, I've moved to the mode-changing solution instead, and based on release instead, since this shouldn't break anything from the user's perspective.