MBG - More natural replay saving, and cleanups/linux

[thearst3rd]

I probably should've split these into two separate PRs so it's easier to view the diffs, but oh well.

More natural replay saving

I was slightly annoyed how if you're recording a replay and finish a level, the game won't record anything else until you exit and restart. So I addressed that and made some small QOL improvements along the way.

• The replay save dialog doesn't appear until after you press "Continue" or "Replay" on the finish screen. This lets you decide if you want to save a replay after you've seen the leaderboard, for example if you can't remember your exact PB time. It's also more in line with PQ.
• If the user stays on the finish screen for >3s, the demo will stop recording itself to not get too large. This matches PQ I believe
• If the user presses the restart button from the finish screen, the recording will begin again
• The default replay filename will say "Unfinished Run" if someone quits back to the menu mid-level, rather than the current IGT which doesn't mean very much.

Cleanups/Linux

This mostly matches with what I did in #2 but for the MBG branch, and with some other small cleanups.

• Remove marblegame.hl which shouldn't have been tracked
• Commit cache.dat since git kept nagging me about it. I can't really tell if this file is changing, at least it doesn't seem to be changing every time. And if it is, then does this file actually need to be committed to the repo?
• Remove zyheaps from compile.hxml since that's only needed for android AFAIK and there is a specific android hxml file
• Added build scripts for linux. The resulting executable seems to work pretty well, better than the crashes we get on MBP. The only issue I can spot is that hashlink doesn't support the open file dialog on non-windows, meaning that ironically all of the changes in this PR about replays aren't helpful on linux lol

[RandomityGuy]

Thanks, and cache.dat is important for Mac version since it fails to create it by itself and crashes the game. As for linux file open dialog, you might have to look into Hashlink sources and expose the linux file dialog function from there.