simplify login title
make form secondary section styles more generic
move login form alternative links to after the form
also apply a button style
use simple_form for login form
add TODO about getting the error msg to show
simplify login button copy
make "Log in" two words rather than "login"
make the log in button more salient
add class for wider button style
make the log in button wider
simplify meta title and reuse :title variable
It's not showing because there aren't form errors to display

This is different to the user sign up form because there we're
validating against a model. On this page we don't want to specify
which field was problematic because it's a login form.
Merge branch 'login_page'