JSON output issues

[larsgw]

For some reason, I thought creating my own JSON serialiser was a good idea. It probably isn't:

• 9746f7a9a9b7fa6527a0f4d62d2b16185bc23d07 (commit message: "Make JSON output valid JSON". This was of course already the intention)

• 143

• undefined still isn't handled properly
• It doesn't handle newer data types, like Sets, Maps, Symbols etc. correctly
• There's a perfectly fine JSON.stringify() function available

The only issue is HTML (and arbitrary dict support) that won't work anymore, but I will have to find a different solution to that, possibly with a replacer function.

[larsgw]

A replacer isn't an option unfortunately. New data types and cases like undefined have been addressed, and so has the abundance of comma's, so I guess this is fine for now. The warning is still included, but less visible due to less logging.