[erlang-patches] Relax reltools requirements on excluded applications

[Håkan Mattsson]

When generating cross compiled systems it is rather inconvenient that
reltool requires that even excluded applications are part of the
configuration. The symptom of this is an error claiming that the
application directory is missing.

With this patch, a missing a application directory is now classified
as warning if the application is explicitly excluded.

  git fetch git://github.com/hawk/otp.git hawk/reltool_relaxed_exclude

or viewed here

  https://github.com/hawk/otp/compare/hawk/reltool_relaxed_exclude
  https://github.com/hawk/otp/compare/hawk/reltool_relaxed_exclude.patch

/Håkan