* Merge from Debian. Remaining changes: - debian/patches/ubuntu-branding.patch: add Ubuntu branding (refreshed). - debian/rules: Drop from -O3 to -O2 to work around a build failure. - d/{control,rules,nginx-core.*}: add new binary package for main, nginx-core, which contains only source-tarball-included modules and no third-party modules. * Add dep8 smoke test