Develop integration w08

Summary of changes:
- various bugs fixed
- pre-commit script for better indentation: see commit 068ce4ca
  For the moment, each contributor has to enable the script (and install astyle) by hand.
  Maybe at some point the script will be mandatory.

See merge request !124

Before that the scaling was aplied in precoder.
Now it is done in sqrt_rho_a and sqrt_rho_b.
For TM4 there still remains 1/sqrt(2) instead of
1/2 both at the transmitter and receievr side.

The warning was:

------------------------
In file included from /roux/openairinterface5g/openair2/UTIL/LOG/log.h:306:0,
                 from /roux/openairinterface5g/openair1/PHY/defs.h:54,
                 from /roux/openairinterface5g/openair2/LAYER2/MAC/eNB_scheduler_ulsch.c:33:
/roux/openairinterface5g/openair2/UTIL/LOG/log.h: In function 'printMeas':
/roux/openairinterface5g/common/utils/T/T.h:94:26: warning: format not a string literal and no format arguments [-Wformat-security]
 #define T_ID(x) ((struct T_header *)(uintptr_t)(x))
                          ^
/roux/openairinterface5g/common/utils/T/T.h:29:22: note: in definition of macro 'T_PUT_int'
     int T_PUT_var = (val); \
                      ^
/roux/openairinterface5g/common/utils/T/T.h:269:7: note: in expansion of macro 'T_HEADER'
       T_HEADER(t); \
       ^
/roux/openairinterface5g/common/utils/T/T.h:101:76: note: in expansion of macro 'T3'
         n18,n19,n20,n21,n22,n23,n24,n...

Conflicts:
	openair1/PHY/LTE_TRANSPORT/dci_tools.c

adding a client-side pre-commit script. This script needs to be installed by every developer manually. see comments in script.

Let the user see how many warnings a compilation generates.
The goal is to have 0 warning, for any compiled component
of openair.

Develop integration w07

See merge request !116

Summary of changes:
- integration of branch tm4-fixes (feature-59-tm4 + somes fixes)
- integration of branch enhancement-199-nas-multi-ue
- integration of branch develop-realtime-lts
- integration of branch enhancement-211-snapping
- various bugfixes

Prior to this commit, the following command failed to build dlsim:
    ./build_oai --phy_simulators -c

Choice has been made to define it in a .h file as a static inline
function.

The command line to get the error was:
    ./build_oai --eNB -w EXMIMO -c

The command line to get the error was:
    ./build_oai --eNB -w EXMIMO -c

We now have 4 versions of T_HEADER:
 - bad quality C++ version with time
 - good quality C version with time
 - bad quality C++ version without time
 - good quality C version without time

The compilation line was:
    ./build_oai --eNB -w USRP

The file openairinterface5g/cmake_targets/log/lte-softmodem.Rel10.txt
has been checked and all LOG_X (and 'msg') warnings have been fixed.

Not sure that it's correct, but those #pragma seem
to be of no use for gcc. Let's remove them
completely.

When rebuilding oaisim, I had a failure because the target
link already exists. The -f flag forces the link to be done.

- some cleanup
- thread names to include UE Mod_id
- arg of UE_thread_rxn_txnp4 to be struct rx_tx_thread_data again
- sync in UE_thread_rxn_txnp4 to use instance_cnt_rxtx again
- UE_thread to call itti_send_msg_to_task with UE->Mod_id + NB_eNB_INST
  instead of INSTANCE_DEFAULT again

This may break the softmodem UE, to be tested.
The most problematic thing may be the synchronization.
I don't think it will impact the processing at all,
but I won't bet my shirt on it.

git show -p 58052152
to see what it's about

git show 157707b0
to see what it's about

- build script has ability to indicate location for downloading uhd images
- one simple wrapper to set environment variables and initiate another program (supposed to be lte-softmodem)

Many variables were changed that should not have been changed.

This reverts commit d31634c3.

Laurent Thomas had a problem on one machine with the build_oai
way of checking for nettle.

The problem with the alternative solution of including nettle/bignum.h
is that it is very unclear.

The problem with nettle is that the file nettle/config.h does not
exist for version 2. It was introduced in version 3.

We want to support both versions, but there is an API incompatibility.
So we need an #if #else mechanism.

The file nettle/bignum.h is present in both versions 2 and 3 and it
includes nettle/version.h in the version 3.

So by including this file, we can check for the existence of
NETTLE_VERSION_MAJOR (that comes from nettle/config.h) in the
code.

But as you can see, the reasoning is way too complex.

So it's better to keep the check in cmake_targets/CMakeLists.txt.

As long as we support version 2 this will be the way to go.

It is possible to force a given version in specific non-generic
customized environments.

Merge branch 'develop' of https://gitlab.eurecom.fr/oai/openairinterface5g into various-l2-fixes-187

Conflicts:
	openair1/PHY/LTE_TRANSPORT/if4_tools.c
	targets/ARCH/ETHERNET/USERSPACE/LIB/eth_udp.c
	targets/ARCH/ETHERNET/USERSPACE/LIB/if_defs.h
	targets/PROJECTS/GENERIC-LTE-EPC/CONF/rcc.band7.tm1.if4p5.25PRB.lo.conf
	targets/PROJECTS/GENERIC-LTE-EPC/CONF/rcc.band7.tm1.if4p5.50PRB.lo.conf
	targets/PROJECTS/GENERIC-LTE-EPC/CONF/rcc.band7.tm1.if4p5.50PRB.usrpb210.conf
	targets/PROJECTS/GENERIC-LTE-EPC/CONF/rru.band7.tm1.if4p5.25PRB.oaisim.conf
	targets/PROJECTS/GENERIC-LTE-EPC/CONF/rru.band7.tm1.if4p5.50PRB.oaisim.conf