Merge remote-tracking branch 'origin/bugfix-234-rlc-um-max-header-size' into develop_integration_w15

Fabrice Nabet (TCL) suggests the value 128 for both.
See https://gitlab.eurecom.fr/oai/openairinterface5g/issues/234#note_3179

The constant RLC_UM_SEGMENT_NB_MAX_LI_PER_PDU is set to 24. This is
too low. Running a downlink TCP iperf with a 10MHz or 20MHz cell
leads to lots of the following warning in the log:

[RLC][W][SN 792] Bad RLC header! Discard this RLC PDU (size=618)

The problem is that the uplink RLC PDU contains a lot of TCP ack.
We can see much more than 24 of them. The RLC layer is not happy
and discards the PDU.

Putting 256 for RLC_UM_SEGMENT_NB_MAX_LI_PER_PDU (arbitrarily chosen,
big but not too big) solves the problem, at least for 10MHz.

it was:

    *num_li_pP >= RLC_UM_SEGMENT_NB_MAX_LI_PER_PDU

it should be:

    *num_li_pP > RLC_UM_SEGMENT_NB_MAX_LI_PER_PDU

develop_integration_w14 into develop

Summary of changes:
- minor bug fixes, minor improvements

See merge request !173

Using "system" to call "git log" is too error-prone.
In the test setup, lte-softmodem was blocked because
"git log" uses a pager ("less") and the pager was
waiting for the user to press enter.

We could pass "--no-pager" to "git log" but then
what if someone runs the softmodem out of the source
tree?

cmake defines PACKAGE_VERSION, we can use that instead,
as is done in openair-cn.

This reverts commit 7f24927c.

With value 13 uplink TDD for a 10MHz configuration was not working.
UDP traffic sent with: "iperf -c XX -u -b10M" was crashing
the eNB.

Develop integration w13

Summary of changes:
- RLC AM reworking (a lot has changed)
- several bug fixes
  * support processing multiple MAC RAR control elements in a single MSG2
  * fix ACK/NACK resetting
  * do not correct USRP frequency from carrier offset estimation when --ue-carrier-scan == off
  * fix TDD uplink due to incorrect PUCCH format for SR in TDD
  * several other simple fixes
- better support for LMS SDR

See merge request !168

- define _GNU_SOURCE before including pthread.h
- do not use static for the array 'threadname' used
  to store the name, it makes it a global variable
  accessed by several threads in parallel
- increase size of 'threadname' (maybe not necessary)
- properly indent #define / #under (# should be at column 1)

When you ran it with the scope as:

    ./dlsim -X

you saw no activity in the "PDSCH I/Q of MF Output" window,
so matter what SNR you put (even for very high SNR, say: ./dlsim -X -s40)

this commit seems to fix it.

I am not sure it is the end of story. The 2 threads PDCCH/PDSCH structures
may still not be used correctly everywhere.