Merge pull request #784 from franckstauffer/fix

HHVM Compatibility - Core and Plugins
Refactoring Mail sending management for backoffice usage
Merge pull request #785 from renaudJennyRBS/master

Refactoring Mail sending management for backoffice usage
Active correction on brands
Create directive for the publication section of forms
Fix directive name
Fix directive status
Add correction on collection item
Fix simpleform locales
[FIX] Set an empty array as default value for availableWebStoreIds parameter in WebStoreSelector block.
Update cart in the frontoffice order process
 - new action UpdateCart
 - new objects for coupons and shipping modes in cart (Rbs\Commerce\Process\BaseCoupon and Rbs\Commerce\Process\BaseShippingMode)
Fix collection item create
[FIX] Head menu dropdowns should be over the website navbar.
Merge pull request #786 from loiccouturier/master

Add corrections on some documents. Enhance some directives
Merge pull request #787 from intportg/dev

Update cart during the frontoffice order process + fixes
- Fixed list of changes in editors in case of same sub-documents.
- Load default values from the server for new documents.
Prevent tags from being loaded for new documents (with ID<0).
Added `<rbs-document-chained-select/>` directive to allow selection of a document with multiple and chained select inputs.
Fixed styles for fields that have errors after saving a Document in an Editor.
Merge pull request #789 from fredericbonjour/Admin

Editors: added default values for new documents and fixed style for erroneous fields. Added <rbs-document-chained-select/> directive.