Use login_email from the session so we can use it at a later date to prepopulate the login
Merge branch 'raf' of github.com:watg/spree_auth_devise into raf

# By Martin Tomov
# Via Martin Tomov
* 'raf' of github.com:watg/spree_auth_devise:
  Email stored as a session variable.

Conflicts:
	lib/views/frontend/spree/checkout/registration.html.erb
	lib/views/frontend/spree/shared/_login.html.erb