[*] MO : crossselling - moved javascript include into header hook.
[-] MO : crossselling - Added in condition to test element is present.
[-] BO: don't have the delivery PDF - User can define which statuses show the delivery PDF
[-] FO: need id_product_attribute to know quantity
Update classes/cache/CacheMemcache.php
[-] Fix: OrderHistory::changeIdOrderState

&$id_order break compatibility with existing codes :

1/ it's unnecessary : Objects are passed by references by default
2/ it causes fatal errors: 
```PHP
$foo->changeIdOrderState((int)$id_order_state, (int)$id_order);
```
Fatal error: Only variables can be passed by reference
[*] FO : Fix #PSCFV-6122 for better adresses aliasing in shopping-cart
// initialize also the link in config.inc.php for retrocompatibility
[-] CORE : fixed bug #PSCFV-4523 - Static _PS_DEFAULT_CUSTOMER_GROUP_ is still use in code even if deprecated 1.5.0.1
// small fix
[-] BO : bad initialization of context due to miss define of _PS_ADMIN_DIR_ in displayImage.php
Merge branch 'development' of https://github.com/PrestaShop/PrestaShop into development
[-] BO : fixed bug #PSCFV-4668 - added check if module folder is writable before upgrade it
//small fix
//small fix part 2
[-] BO : fixed bug #PSCFV-4961 - Strange behavior when reordering categories
// performances improvement
// small perf optimization
[-] FO : fixed bug #PSCFV-5312 - Error Uncaught TypeError: Cannot read property top of null in ajax-cart.js when Cart Block is not on product page
Merge branch 'development' of https://github.com/PrestaShop/PrestaShop into development