[+] Project: add the possibility to change the default color (#db3484)

Let the user set the default color in the mail with a color picker (configuration set in Back Office, Themes)
order carrier more compatible with opc

The carriers' block didnt't have the 'opc-main-block' in the order-opc page.
order-carrier more compatible with order-opc

carriers' block didn't have the opc-main-block when in opc-order
order-carrier more compatible with order-opc

carriers' block didn't have the opc-main-block when in opc-order
move header tag out of carrier block
Fixed variable typo (redution instead of reduction in some places)
[-] FO : mobile template - states management
[-] MO : fixed backslashes in homeslider #PSCFV-5664
// config.xml in english
[-] BO: Fix various bugs in categories ntree generation
[-] BO: Fix root category should anyway be imported in shop creation #PSCFV-5885
// replace bad attribute name
[-] FO : jquery mobile was not compatible with js minifier, I updated both
// Fixed stripos !== false in module search
[-] CORE : fixed bug #PSCFV-6098 Double @ in customer email address crashes BO
[-] BO: Improve memory usage in admin product in global context with a lot of shops and attributes
[-] BO: don't display stock available if stock management is disabled #PSCFV-6029
[-] CORE : fixed bug #PSCFV-6084
Merge branch 'development' of https://github.com/PrestaShop/PrestaShop into development
[-] FO: CLONE - order_conf still not fixed propertly #2 - #PSCFV-5817