The encoding option was introduced in commit
270d909696a753af022df72a404c73f2895b4a02, to allow report callbacks to
format according to a given encoding. There was, however, no
connection between this encoding option, and the encoding of the
device to which the logger handler was writing.

Since a formatter is defined to return unicode:chardata(), and in
order to avoid mismatch with the encoding of the device, the encoding
option is now removed from the formatter. The handler itself must make
sure that it does not write illegal data to its device.

* siri/supervisor/warn-shutdown-race/ERL-724:
  [supervisor] Add warning about race condition

ERL-724: "During a 'gentle' shutdown, supervisors unlink from their
children before sending shutdown signals to them. This can lead to a
race condition in supervision trees, when the timeout for gentle
shutdown of a parent supervisor expires and it kills a child
supervisor that has just unlinked from a child of its own, leaving the
child supervisor's own child still running after its supervisor is
killed."

This commit adds a warning about this in the documentation.

* rickard/pcre-8.42/OTP-15217:
  Update PCRE from version 8.41 to version 8.42

* sverker/erts/ets-memstat-false-leak/ERL-720/OTP-15278:
  erts: Refactor ets FixedDeletion allocations
  erts: Fix ets memstat false leak of FixedDeletion

causing erlang:memory to report too much ets memory.

It can also return errors and warnings.

stdlib: Let dets:open_file() crash when given raw file name