on login form pass returnto and returntoquery parameters to create account

A user may attempt to login then realise they've forgotten their password and
click create account. Let's ensure we pass returnto and returntoquery parameters
so we can get an accurate picture of which ones created their accounts because
of watching articles and ensure their first article gets watched

Change-Id: I0fb37157dca12f4704e0acf85d79098587f83354
Merge "on login form pass returnto and returntoquery parameters to create account"