[+][SUG][PL/ED] Keep playtest replay in memory

[WillLem]

From Guigui in this topic.

I'd appreciate if replay carries when using the editor.
To be clearer : create a level, playtest it, exit to editor to make changes, play test the level again and find your previous replay ready for you.

[WillLem]

Good idea.

The question is really how to do this. We can store a temporary replay file in the directory which always keeps the same name, updating the internal data whenever a level is playtested. If we're in Playtest Mode and the replay data matches the level, we load the replay. Otherwise, we only overwrite.

There may be a better way, though. My goal would be to not litter the directory with temporary replays, ideally.

Suggestions welcome.