Move the account login link to a method for easier subclassing.
Use the new account login uri config setting when relocating to account login.

Requires https://github.com/silverorange/site/pull/83
Allow null type on StoreCheckoutPaymentMethodPage
Other parts of the the page allow for null type. Make processing also allow for it
Merge pull request #38 from nburka/allow-for-null-payment-type

Allow null type on StoreCheckoutPaymentMethodPage
Merge pull request #37 from isaacgrant/account-login-uri-as-config-setting

Use the new account login uri config setting when relocating to account login.
Merge pull request #36 from isaacgrant/subclassable-account-login-link

Move the account login link to a method for easier subclassing.