This allows additional data roundtripping through JSON since to_json() already
supports tables. There are some subtleties around the formatting of strings in
JSON object keys, for which this adds a bit of helper infrastructure.
This also expands the language.table test to verify the roundtrips, and adapts
bif.from_json to include a table in the test record.
The from_json() BiF and its underlying code in Val.cc currently expect ports
expressed as a string ('80/tcp' etc). Zeek's own serialization via ToJSON()
renders them as an object ('{"port":80, "proto":"tcp"}'). This adds support
for the latter format to from_json(), so serialized values can be read back.
* amazing-pp/topic/fupeng/from_json_bif:
Implement from_json bif
Minor updates during merge: Moved ValFromJSON into zeek::detail for the
time being, removed gotos, normalized some error messages to lower case,
minimal test extension and added a raw reader input framework test reading
"json lines" as a demo, adding notes about the implicit type
conversions.