Merge pull request #135 from mrpollo/usps_missing_services

Usps missing services fixes #134
Bump to active_shipping 0.11.0

Fixes #136

Conflicts:
	spree_active_shipping.gemspec
rate calculations per package not by order
added some helper functions as well to cleanup some of the code
also made sure the weight tests where using packages instead
of orders and that they still made sense
Merge pull request #138 from mrpollo/calculate_weighs_per_package_contents

rate calculations per package not by order line items