Add openDevice() for Input and Output classes.

include/Input.h

include/InputFile.h

include/InputSerial.h

include/InputSocketServer.h

include/Output.h

include/OutputFile.h

include/OutputSerial.h

include/OutputSocketClient.h

src/InputFile.cpp

src/InputSerial.cpp

src/InputSocketServer.cpp

src/OutputFile.cpp

src/OutputSerial.cpp

src/OutputSocketClient.cpp