A new logger is there: the "ticked TTI logger".
Similar to TTI logger (used by the PUCCH1 energy plot)
but takes another input, the "tick" (think subframe)
and a default value for when no event is triggered between
two ticks.

This is used for the UL and DL MCS plots in enb.c (next commit).

iqlog.c should change its name, it's too specific.
This new one is more generic and should take over the name.

the current version is very specific to PUSCH IQ data, where the
input buffer has a special format

to be rewritten cleanly at some point

events are accepted by the logger if the filter accepts them
the filter is optional (no filter means to accept all events)

this is like timeview but the plotting is done at frame/subframe
resolution of a given reference clock signal, let's say.

The realtime information of the events is not used. It's all
logical.

It will be used to log harq processes for the moment.

not very clean, might be reworked at some point
the idea is to compute much less 'log' than what
was done

not tested