FifoQueueBase: make the class usable when used not as base for inheritance
FifoQueueBase: make the class usable when used not as base for
inheritance

Make user functions public instead of protected, make some types public
instead of private
CezaryGapinski/distortos,DISTORTEC/distortos,CezaryGapinski/distortos,jasmin-j/distortos,CezaryGapinski/distortos,CezaryGapinski/distortos,jasmin-j/distortos,DISTORTEC/distortos,jasmin-j/distortos,DISTORTEC/distortos,jasmin-j/distortos,CezaryGapinski/distortos,DISTORTEC/distortos,jasmin-j/distortos