[BUG][PLAYER] A few bugs in test play mode.

[namida]

Gonna keep these all in one place until I actually look into them and figure out how related they are or aren't.

All of these are discovered in current development source code, and may or may not apply to the stable version. None are critical though.

Bug 1 - It's still possible to open the level select menu at certain points during testplay mode. For example, at the preview screen.

Bug 2 - Using testplay mode appears to overwrite the last played level, meaning NL forgets next time it's run. This may be a side effect of invoking bug #1, I haven't looked in isolation to see if it occurs even without invoking #1.

Bug 3 - If you play a level in standard mode, exit NeoLemmix (so that this level is the "last level played"), then delete or rename its level file (even if the levels.nxmi files are updated accordingly, where applicable), then run NeoLemmix in test mode, you get an error message popping up before NL starts (however, it still runs as normal once the error is dismissed, as far as I can tell). This doesn't happen when running NL in standard mode.

[namida]

#1 and #2 (the latter of which was unrelated to #1) fixed in commit 65CDB3A. Still need to look into #3.

[namida]

Okay, looks like either something else I did at some point fixed #3, or I was incorrect in one of the details about it (eg. maybe I hadn't actually updated levels.nxmi?).