Covering feedback from @dhensby; cheers Dan.
FIX Readme edits

Added comments to the config examples as well as a link to the Opauth docs.
Moved an FAQ item.
Minor formatting.
FIX Readme

Added more links to Opauth Docs
Merge branch 'master' of https://github.com/BetterBrief/silverstripe-opauth
Cleaning up controller
Unscrewing the validation step
merging with Dan