As a temporary measure to ease the transition to default UTF-8
encoding, automatically fall back to the Latin-1 encoding (without any
warnings; the Erlang Compiler will emit a proper warning).

The intention is to remove this workaround in OTP 18 or 19.

There was a copy-paste bug in erl_syntax when running
e.g. erl_syntax:revert_forms, affecting maps. Instead of getting
Key/Value you got Key/Key in the resulting abstract form.

The added test case tests a bug when reverting maps in syntax tools.

Most dependencies introduced are exactly the dependencies to other
applications found by xref. That is, there might be real dependencies
missing. There might also be pure debug dependencies listed that
probably should be removed. Each application has to be manually
inspected in order to ensure that all real dependencies are listed.

All dependencies introduced are to application versions used in
OTP 17.0. This since the previously used version scheme wasn't
designed for this, and in order to minimize the work of introducing
the dependencies.

Ensure all are "normal" versions according to the new version scheme
introduced in OTP 17.0

Thanks Kostis.