Added compatibility for new M2M relationships
* Added support for user language setting
Fixed: Fatal error during activation when cURL extension is not enabled on the server. Fixed: Layouts CSS is not imported when one of the resources is missing. Fixed: JS errors when using ampersands and other special characters in module names. New: Validate module names to accept only a-z, A-Z, 0-9, hyphen, and space characters. New: Localization files. New: Validate if module contents are valid inside an imported zip file.
