v0.6.0

A stream ends at the first record it cannot read, so the next program in
a pipeline never sees a partial result that looks complete, and
--stop-on-error goes away with the choice it offered. jz new KEY:=JSON
returns the same status as the same text read from a file, and the
registry reads what exiftool, identify and pkg-config print: 227 commands
through 600 definitions.

Added

• Four definitions for what three tools print: exiftool FILE (the tags
  one per line) and exiftool -G FILE (the group in front of each of
  them), identify FILE... (one record per image, its width and height
  typed), and pkg-config --list-all (the modules it knows, read only
  when named since a name and a phrase is also what a glossary looks
  like). The registry holds 227 commands through 600 definitions.

Fixed

• jz new KEY:=JSON returns 3 rather than 2 when the argument is JSON
  and jz refuses what it holds: a key given twice in one object, or
  nesting past the depth limit. The same text in a file (KEY:=@f.json)
  and the same text read as data (jz --format json) already returned 3,
  so a script that built the argument with a command substitution got a
  different status from one that passed the file. Text that is not JSON
  at all is still 2, since that is the command line being wrong.

Changed

• A stream ends at the first record it cannot read, rather than leaving
  the record out and going on. --stream, jz run --stream and jz new --each all do this, for a command's output, a data file and lines or
  nul alike: the records written before the failure stand, it is
  reported once on standard error, nothing after it is read, and the
  status is 3. A stream that goes on past a record it dropped reaches the
  next program in the pipeline looking complete, since the diagnostic
  went to standard error and the status comes only after the records have
  been read and acted on.

Removed

• --stop-on-error asked for what every stream now does. A command line
  that still names it is refused with exit status 2 and a message saying
  so; drop the option and the behaviour is unchanged.
• engine.Stream no longer takes an onError func(*ParseError) error
  beside emit: with one answer to a record that cannot be read there is
  nothing to choose. A caller passing nil today drops the argument and
  gets the same reading.