Changed many functions in the abstract *Link classes to be const. This facilitates setting other functions as const. The metadata for specific links are reset when the links are added.

Changed many functions in the abstract *Link classes to be const. This facilitates setting other functions as const. The metadata for specific links are reset when the links are added.

Set the remote address of the xbee via the xbeeconfiguration window and save last address in a txt file. Xbeelink ist still hardcoded to work with series2 xbees