Properly escape inline JSON as HTML
Properly escape inline JSON as HTML

Simply replacing `</` with `<\/` is not sufficient for escaping HTML,
because `<script>` and `<!--` have a special meaning in the HTML5
parser too.

Besides that, not escaping `&` leads to edge cases where the result is
incorrectly interpreted.

bill-mccloskey/mozsearch,bill-mccloskey/searchfox,bill-mccloskey/mozsearch,bill-mccloskey/mozsearch,bill-mccloskey/searchfox,bill-mccloskey/searchfox,bill-mccloskey/mozsearch,bill-mccloskey/searchfox,bill-mccloskey/mozsearch,bill-mccloskey/searchfox,bill-mccloskey/mozsearch,bill-mccloskey/searchfox