Add the option to use a hosted domain with google's oauth

The hd option is used to restrict which email domain that are allowed to
log in to your app.

Starting from this commit you can pass `hostedDomain: 'example.com'` to
only allow emails from the domain `example.com`.
Implement Accounts.config({ restrictCreationByEmail: 'mit.edu' })

- Check email for users created with password or any social account's email
- Throw an error with explanation on bad email domain.
- Set `hd` param for Google Accounts authentication url
- Docs description
- Touch History.md

- Possibly should add it into QA process?
Merge branch 'pr-1332' into devel