Write config directly to buffer instead of memcpy of config struct.

This removes the need for big/little endian switching during reading the
configuration on the Java side
Add method to check if pins are used by a certain feature
Refactor reading/writing of configuration, implement missing parts
Define missing error constants
Store created feature in repository (!)
Confine special bootstrap code to RiConfig
use correct variable for sizeof
Use correct method name and shift operator.

There went another 2 hours of my life...
Use correct offset for config.

(Yet another wasted hour...)