Switch media list files to JSON

[cycomachead]

While JSON has a little more syntax the current file format, it would be quicker to parse (native parser) and we wouldn't have to worry about any edge cases that come up if we want to have descriptions that contain newlines and other things.

[PullJosh]

JSON is also easier to read, for what it's worth.

[jmoenig]

Can you tell me which problem this solves? Is there an issue with newlines in our XML format? If so, we should fix it, right?

[cycomachead]

I'm talking about the LIBRARIES / COSTUMES / SOUNDS etc files. The current files are a really loose new line and tab delimited format. It was better than scraping and parsing the HTML response pages, but there's definitely been a couple cases where a line doesn't correctly contain a tab character, and now BH gave me verbose descriptions for the new libraries, and those could be more nicely formatted.

(Of course, I could (in theory) adapt the 'parser' for the current format to handle more newlines or escapes, but it seems simpler and less error prone to use JSON.)

[jmoenig]

Ah, now I see. Thanks!

[BookOwl]

I created a PR for this in #1621