profiles: rebase onto Gentoo's hardened profile

The default 10.0 is deprecated and removed upstream. Also, instead of
twiddling the hardened flag we should just use the hardened profile.

As part of this the host SDK no longer has multilib enabled, it isn't
actually needed for anything anyway.
profiles: disable static binaries

Left over from some odd behaviors of the ChromeOS build systems.
hard-host-depends: remove google-breakpad

This package does not build in the SDK after removing multilib support.
We don't actually need it, kill it.
docker: sync ebuild with latest version in Gentoo

Most of the change here isn't significant except for the compilation
fixes for compiling with a hardened compiler. This was not an issue
previously because the SDK's cross compiler wasn't hardened.
systemd: work around broken configure test for -Wl,-fuse-ld=gold
Merge pull request #783 from marineam/updates

Prepare for updating portage-stable and some cleanups