Fix install_generator.rb

An errant '-' prevents the installer from running.
url variable isn't defined, added it from latest spree
Merge pull request #53 from jdatti/master

url variable isn't defined and getting a runtime error because of it, added it from latest spree
Mark the last breadcrumb with the 'active' class.
Merge pull request #55 from berkes/master

Mark the last breadcrumb with the 'active' class.
Added new user session form rendered directly from checkout
Merge pull request #59 from sanchojaf/user_session_in_checkout

Added new user session form rendered directly from checkout
Manually merge 2-2-stable PRs together
Merge branch 'master' into 2-2-stable