Stable 1.x

[stefanpenner]

I've created a 1.x stable branch, so that we can re-publish 1.2.1 without tmp and with the files whitelist.

This PR exists as a way to make sure me and @joliss sync up, and are both aware of this.

cc @joliss

[stefanpenner]

Ah, also apparently I cannot publish. @joliss can give me publish on npm?

[joliss]

Thanks! The master branch is still compatible, so we don't need a separate stable-1.x branch. I've rebased this on master and released 1.2.2, and updated the v1.2.2 tag with my rebase as well.

I've added you on npm to broccoli-plugin, and broccoli-source as well.

I generally prefer .npmignore over package.json by the way, since if we add another module in the future we might forget to update the "files" field and push a broken distribution. I've pushed fdce2ab to that effect.