Bob Shannon authored Sep 10, 2018 and Torkel Ödegaard committed Sep 10, 2018

* Allow oauth email attribute name to be configurable

Signed-off-by: Bob Shannon <bshannon@palantir.com>

* Document e-mail determination steps for generic oauth

* Add reference to email_attribute_name

* Re-add e-mail determination docs to new generic-oauth page

* Inherit default e-mail attribute from defaults.ini