0.4.1 [2016-09-22]

• 5cdb8fa: [autoname] avoid failure if UCI files are empty
• #24: added mac_interface option, defaults to eth0 (thanks to @agabellini)
• b09a497: [registration] send mac_address parameter to openwisp2 controller
• e8f0b35: [reload-config] log which services have been reloaded