add Hooks API

C. Fahner <christiaanenzo@gmail.com>
add ApiCall core/setting_save

C. Fahner <christiaanenzo@gmail.com>
make SettingsService->listAll() static

C. Fahner <christiaanenzo@gmail.com>
add prefix parameter to listAll

C. Fahner <christiaanenzo@gmail.com>
add prefix parameter to the ApiCall core/settings_list

C. Fahner <christiaanenzo@gmail.com>