Implemented Returned Orders like any other Order.

 Fix Image Conversion by using sRGB instead RGB, because it seems that using
 'sRGB' instead of 'RGB' makes a good result for RGB input, because imagemagick
 assume that input's colorspace is sRGB if not specified.

It includes minor improvements.

 Introduce temp_object parameter on builder.build() and propagate it
 over until the newContent() calls. This change allow use create
 Temporary Documents intestead real ones, like a "preview".

Person information must be consistent, so it allow any project define appropriate constraints.
You can only progress if you are logged in, otherwise show a button to user to login form.

Renamed SaleOrder_finalizeShopping to WebSection_finalizeShopping.

* This commit should be rebased before be really released.

SaleOrder_viewConfirmAsWeb is a duplication of SaleOrder_viewAsWeb

Enable SaleOrder_isShippingRequired implementation
Optimize SaleOrder_isShoppingCartEmpty

We use field instead to present such information.

- SaleOrder_viewAsWeb (previously SaleOrder_viewDetailAsWeb) is now the SaleOrder_view in web mode, where it is used to view the previous Sale Orders informations.
- WebSection_viewShoppingCart is now the shopping cart (previously was calledSaleOrder_viewAsWeb)

- Introduce improvements on current forms in meanwhile.

Fix name convention on forms and use login_form instead register section for request the user login.

- Removed unused code which has no meaning to keep (Just ramdom scrips)
- Moved to erp5_commerce_paypal_legacy code only used by PayPal Legacy related code.

Those forms are been not used or not working

This code is considered as legacy because it is not yet compatible with SecurePayment and it is implemented with "Express Checkout" in mind which is not
suitable for all web sites that intent to use Paypal.

Use web_view instead a web section to view person information
Simplify Person_viewAsWeb and drop usage of websection
Updated Persion_editPersonalInformation (Done by JP mostly)

Use SaleOrder_viewAsWeb instead ad-hoc name.
For e-commerce, we do not allow user edit his own order on web mode.

Use erp5_ui_short cache on Products List