* mhssler/doc-os-unsetenv-unicode:
  stdlib: Document os:unsetenv Unicode support

In OTP 17 it is possible to mix types such as dict:dict() and
dict:dict(_, _) outside of the dict module (and similarly for some
other opaque types in STDLIB), but the results are unfortunately
possibly invalid warnings in users' code. In OTP 18 parameterized
opaque types with the same name but with different number of
parameters are no longer compatible when seen from outside of the
module where the types are declared.

The types in STDLIB have been updated accordingly; for instance
  -opaque dict() :: dict(_, _).
has been replaced by
  -type dict() :: dict(_, _).

Several people have requested that the assert macros in EUnit should be
moved out to a separate header file. This patch puts them in
stdlib/include/assert.hrl, which gets included by the eunit.hrl file.
Thus, nothing changes for eunit users, but the asserts can now also be
included separately.

* fishcakez/supervisor_ignore:
  Don't store child that returns ignore in simple supervisor

OTP-12793

With parametrized types and specs, modules using
orddict can be statically checked with dialyzer.
Although orddict have not been builtin types, it is
good and more natural to have its exported types and
specs aligned to builtin types.

If a child of a simple_one_for_one returns ignore from its start
function no longer store the child for any restart type. It is not
possible to restart or delete the child because the supervisor is a
simple_one_for_one.

Previously a simple_one_for_one would crash, potentially without
shutting down all of its children, when it tried to shutdown a child
with undefined pid.

Previous only one undefined pid child was stored in a simple_one_for_one
supervisor no matter how many times the child start function returned
ignore.

* sverk/ets-tab2file-syn/OTP-12737:
  stdlib: Add 'sync' option to ets:tab2file/3

Document that os:unsetenv/1 handles Unicode in the same way as os:getenv
and os:putenv.