* join pthread_FH (ru_thread) once all condition variables have been set
* join RU FHTX only if it has been started (check as for pthread_create())
* join PRACH thread in the monolithic case
* send broadcast on condition variable cond_eNBs, as there can be multiple
  waits on it
* integrate stop_ru(*ru) into kill_RU_proc(*ru)
* Correct memory freeing

LOG_F replaced by LOG_DUMPMSG. Add a generic function to dump a buffer or message. Go on with LOG_M implementation improvement. Remove redundant options to enable/disable logs.

USRP addressess and clock sources can be configured in the configuration file with the RU section with comma separated IP addresses in 'sdr_addrs' and with strings "internal"/"external"/"gpsdo" in 'clock_src'.

TODO: Currently the driver picks the two first RX and TX channels when nb_tx and nb_rx are both set to 2. If a developers wants to force usage of two devices, 'set_rx_subdev_spec' and 'set_tx_subdev_spec' can be used to indicate to the driver so that antennas from separate devices will be used. To rephrase: until 4 antennas are supported by OAI, testing with two devices, so that antennas from both devices are used, requires manual configuration of which subdevices' antennas are used.

Conflicts:
	targets/ARCH/USRP/USERSPACE/LIB/usrp_lib.cpp

log.c simplification, fix usefull functionality which never worked, move all log code from openair2 to common

Remove compilation warnings, also fix telnet server compilation failure and NB-IoT shared lib compilation failure introduced when reviewing L1 sources  organization

We have to not call that function here because
it blocks everything if number of proc > 4.

UE directory splits, creation of UE-specific files, common UE/eNB files and extraction of UE/common components from eNodeB files. renaming of files to minimize common names across directories (i.e. defs.h, vars.h, extern.h)

1. Previous SW configuration for different RRC version relies on whether macro Rel10,
   Rel14 defined or not by checking #ifdef Rel14 or #if defined(Rel10) || defined(R14).
   Whenever there is a newer RRC version, e.g. Rel15, it will be very a tedious and
   error-prone job to add defined(Rel15) in every place.

2. Some RRC messages are defined in release 13 instead of release 14, NB-IoT
   feature is one of such example. Our code shall reflect this fact instead of using
   an afterward version number in software configuration.

3. Some RRC messages or some fields of certain RRC messages are added in the middle
   a release, e.g. SystemInformationBlockType1_v1310_IEs_t defined in RRC 13.1.0
   and RRC 9.2.0 made some changes to SIB12 and SIB13 so we have sib12_v920 and
   sib13_v920 fields in SIB12 and SIB13's struct.
   We need a finer grain of control when using ASN1 from different RRC version.

4. S1AP also has this problem that it use UPDATE_RELEASE_9 and UPDATE_RELEASE_10 to
   differentiate between various S1AP version.

This commit propose using MAKE_VERSION(x,y,z) to designate the version number and
modify current conditional compilation accordingly.

Note: 2018/04/16, Modified based on Cedric's comment.

- fix compilation of dlsim/ulsim/oaisim by defining some needed
  global variables
- fix compilation of oaisim: compile coding and params_libconfig
- fix running of if4p5 with low CPU count (oaisim was not working
  on the machine 'haswell' because of this)

When the program exits it has to stop the streaming of the USRP.
The function exit_fun is supposed to do that. When quitting with
control+c (very common case) this function is not called. The
code is very unclear there, so let's add a stop_rf in the RU,
as there is already a start_rf.

If we don't call trx_end_func, then at the next run the USRP
device may be in an unstable state and behave improperly.

If the program crashes then the USRP device may be in an
unstable state. The only solution to this problem is to reset
the USRP device.

Maybe there is a way to clean the state of the device when we
open it, before we start using it. Sort of a cleanup before
use. That could be a better solution to "bad state after program
crash".

What has been tested:
- monolithic eNB only