Some extension

[Phunkafizer]

• Configobject for AfcFei register
• fetch FEI on packet reception
• register areas for freg, fdev, bitrate etc.
• add configuration object for Dio2Mapping
• support reception of different packet types. i. e. large, fixes, variable, unlimited
• reset pin optional; some hardware does not use reset pin
• configurable SPI device in order to use 2nd chip select on Raspberry PI
• more to come soon