Revert "feat(oauth): multiple strategies per account; changeable email"

This reverts commit ef062728a2ec61d990fa87d965f2507b4bcc5b20.

Conflicts:
	app/templates/client/app/account(auth)/settings/settings.controller(coffee).coffee
	app/templates/client/app/account(auth)/settings/settings.controller(js).js
	app/templates/client/app/admin(auth)/admin(html).html
	app/templates/client/app/admin(auth)/admin(jade).jade
	app/templates/client/app/admin(auth)/admin.controller(coffee).coffee
	app/templates/client/app/admin(auth)/admin.controller(js).js
	app/templates/server/api/user(auth)/user.controller.js
	app/templates/server/api/user(auth)/user.model.js
	app/templates/server/auth(auth)/facebook(facebookAuth)/index.js
	app/templates/server/auth(auth)/facebook(facebookAuth)/passport.js
	app/templates/server/auth(auth)/google(googleAuth)/index.js
	app/templates/server/auth(auth)/google(googleAuth)/passport.js
	app/templates/server/config/_local.env.js
	app/templates/server/config/environment/index.js
update changelog
2.0.12