Merge branch 'master' into L2SDP-535

Installing on raspberrypi.md

LOGBOOK

README.md

developing_on_raspberrypi.md

src/Makefile.am

src/config_reader.cpp

src/config_reader.h

src/constants.h

src/fpga.cpp

src/io/ucp.cpp

src/io/ucp.h

src/io/udpsocket.cpp

src/io/udpsocket.h

src/node.cpp

src/node.h

src/opcua/ua_server.cpp

src/periph/fpga.cpp

src/periph/fpga.h

src/registers.cpp

src/registers.h