T: add 'throughputlog' logger

Normally it is used to display throughput.

The computation it does is to sum up the wanted value for the last
second (1000 TTIs) and send this value to the views associated to
this logger, at each TTI.

common/utils/T/tracer/logger/Makefile

@@ -2,7 +2,7 @@ CC=gcc
 CFLAGS=-Wall -g -pthread -I..
 
 OBJS=logger.o textlog.o framelog.o ttilog.o timelog.o ticklog.o iqlog.o \
-     iqdotlog.o ticked_ttilog.o
+     iqdotlog.o ticked_ttilog.o throughputlog.o
 
 logger.a: $(OBJS)
 	ar cr logger.a $(OBJS)