If an end-of-line comment ended with '\', the code that "prettifies"
the JSON output would get confused, and would start inserting \r\n
after commas inside comment strings. This didn't corrupt the project
files, but it did make them look funny, and required manual cleanup.
Added a sample. This won't catch regressions of this particular
problem because it only happens when you save the file, but if
nothing else it'll act as documentation.
