ENHANCEMENT: Introduced hooks for shopping cart interactions.
Merge branch 'release-0.8.5' into develop
ENHANCEMENT: improved pricing system to allow price alterations before template usage.

Renamed db field 'Price' to 'BasePrice', and introduced sellingPrice() function and getPrice() function. The get price function just returns the sellingPrice, which is the place to make modifications to the BasePrice before presenting to the user. This could be a temporary product discount, or member/region specific pricing.

CMS field updates also.

relates to #41
Merge branch 'refs/heads/shoppingcart-hooks' into develop
Merge remote-tracking branch 'refs/remotes/origin/develop' into develop
Merge branch 'refs/heads/62-member-form-data-hotfix' into develop
Merge branch 'master' of github.com:burnbright/silverstripe-shop into develop
Merge branch 'develop' of github.com:burnbright/silverstripe-shop into develop
Fixed product price migration script
Sanity check for shopping cart link generation. Return false if incorrect args are supplied.
Updated upgrading docs with some 0.9, and 0.8 info.
MINOR: Added setPrice on Product that in turn sets BasePrice. Removed updateValidator and updateFields from Order form. Updated docs for extending order form.
ENHANCEMENT: added getPastOrders function to ShopMember
BUG: Javascript validation prevents modifying form for entering separate billing and shipping details.

fixes: #75
Merge branch 'refs/heads/75-checkoutvalidation-fix' into develop
BUG: Item function for Variation was failing, due to still using old code. Added tests to catch future changes.

fixes #70
Merge branch 'refs/heads/70-variation-item-hotfix' into develop
BUG: member details overwrites address details
fixes #72
Merge branch 'refs/heads/72-checkout-member-hotfix' into develop
BUG: When you enter a value using the cart quantity field, it breaks. This is because the setquantity url is not formed properly in the ecommerce.js file.

fixes #76