Backport field name change from 3.x branch

Reviewed-by: macintux

Backport OTP 18 test fixes from 3.x branch

See #334

See #337

Bump goldrush to 0.1.8

Reviewed-by: macintux

Backport fix from #306 into 2.x branch

Reviewed-by: macintux

This mirrors a bump on the master (3.x) branch

Ensure stopped traces remove their event handlers
and actually stop.

See PR #306 for details. This is a backport.

Accept 255 (or 0xFF in hexadecimal) for format strings

At least for ISO 8859-1 (aka Latin-1) [1], 255 is one of its
characters.

[1] https://en.wikipedia.org/wiki/ISO/IEC_8859-1

Update lager 2.x for OTP 17

Reviewed-by: JeetKunDoug

Goldrush 0.1.7 completes the set of operators available for
a filter.

It now tests something slightly different,
but should be sufficient to validate the
behavior is correct.

Add/update file copyright headers where deterministically appropriate.

Note:
Many updates to rebar.config files have been scripted to ensure
consistency and likely have re-ordered configuration settings and options.
While the file may look significantly different, the content other than
dependency updates (and, in some cases, more stringent compilation options)
should be the same from rebar's perspective.

Improve format_reason for certain oddly formed badarg stacktraces

Typos, add formatting, rework the semi-iolist description

add per-module per-function trace example

Fix/make trace stop trace api consistent cleanup

Add optional log_root environment variable

Mention the color atom for the formatter config

Fix specification of backend config in log rotation example