Fixed WIO build error; does not support IOStream::Device::empty().
Merge branch 'master' of github.com:mikaelpatel/Cosa
Merge branch 'master' of github.com:mikaelpatel/Cosa
Allow eeprom upload on caterina bootloader devices (leonardo, micro, etc).
Merge branch 'master' of https://github.com/mikaelpatel/Cosa into add-adafruit-boards