Phasing out i686 support

Due to the decreasing popularity of i686 among the developers and the community, we have decided to phase out the support of this architecture.

The decision means that February ISO will be the last that allows to install 32 bit Arch Linux. The next 9 months are deprecation period, during which i686 will be still receiving upgraded packages. Starting from November 2017, packaging and repository tools will no longer require that from maintainers, effectively making i686 unsupported.

However, as there is still some interest in keeping i686 alive, we would like to encourage the community to make it happen with our guidance. The arch-ports mailing list and #archlinux-ports IRC channel on Freenode will be used for further coordination.

The [multilib] repository will not be affected by this change.