I've noticed that the yocto binaries and sources have been down for five days, so here's some simple instructions to build an edison image without having to go to Intel.
Download sources from github:
git clone git@github.com:ii/edison-src.git
cd /edison-src
./device-software/setup.sh
source poky/oe-init-build-env
touch conf/sanity.conf # if building as root... BUT you shouldn't do that
bitbake edison-image
My version of setup.sh downloads tarballs from this release page rather than embedding them into the git repo.