- lock with mutexes
- don't start ENB_APP task, but Agent directly and wait in case of
  reconfiguration

- {restart,stop}_L1L2() in lte-softmodem.c
- add function start_phy_rrc() in enb_app.{c,h}, accessible from outside
- will be used to restart PHY and RRC when lte-softmodem is restarted

use only one FlexRAN wait function

With the current implementation of oaisim
(rxdata and channel simulation), we cannot
call trx_read_func on a dummy buffer. The
code will actually modify the rxdata buffers
of the UE.

This is has to be rewritten properly. In the
meantime, let's introduce a simple hack. The
idea of the read at this point is to wait for
the synch to finish and not lose samples from
the hardware in the real UE. In the simulator,
as it is today, we can simply sleep until the
synch code has finished its work.

Optimisation of rx_pdcch : save some time by reading one symbol pdcch first and read symbol 2 and 3 if needed
Optimisation of nb of candidate when searching DCI

changes:
- ue mcc/mnc 208.93
- use correct key/opc for user
- change addresses in conf file for them to be easier to understand
  (maybe)

With those changes, running:
   sudo ./run_enb_ue_virt_s1
in cmake_targets/tools should work out of the box

The user still has to configure correct IP addresses in
targets/PROJECTS/GENERIC-LTE-EPC/CONF/enb.band7.generic.oaisim.local_mme.conf

We supposed oaisim (enb+ue) machine to be on IP address 10.0.1.1
and EPC (hss, mme, spgw) machine to be on IP address 10.0.1.2.

Several problems are present.

The first is that _write returns 0 instead of the
number of samples. We solve it by returning
nsamps.

The second is that _read may return less samples at
the beginning and we don't want to exit for that.
We solve it also by returning nsamps.
(We still need to log more in this, to be done in the
next commit.)

The third is that after initialization we don't send
anything for a while, time for the softmodem to finish
its init. This generates lots of "RX overrun".
We solve it by disabling TX and RX modules after init
and then in trx_brf_start we activate them again (and
also call bladerf_sync_config, which seems to be
mandatory, and bladerf_calibrate_dc, which may be avoided,
perhaps).

Maybe not the end of the story. Sometimes it works, UE connects,
traffic is fine (tested only with 5MHz). Sometimes it does not,
UE does not connect, or it connects but then traffic is bad,
especially uplink.

To be refined.

re-adding the possibility in dlsim to bypass the DCI/PDCCH generation. This is necessary for accuracy of the dlsim-tests, which are working again now.

- rename UE_NO_LOG to DISABLE_LOG_X
  because the name is misleading. The full software
  is impacted, not only the UE part
- same for compilation option ---ue-no-log
  that becomes --disable-log
- keep LOG_X for the standard case, that is the
  case without DISABLE_LOG_X where printf has been
  put. Two reasons:
  * printf is not realtime friendly
  * keep behavior similar for other users who may
    be troubled by different logs that don't add
    any benefit to previous logs

The port to use should be 2152, not 2153.

--ue-trace : Enabling UE trace for debug
--ue-timing : Enabling UE timing trace
--ue-no-log : Disabling all LOG_X traces

those popped up thanks to previous commit

- print current working directory
- print git version (if available)
- print security keys
  this last one is a security breach, but as of today
  it's not a problem

No need for this special case. Plus, it fails with the work
from Nokia on compilation cleanup.

----------------------------------------------------------
bug 29

Ttile:
FDD should be TDD.

Bug Location:
  switch (oai_emulation.info.frame_type[0]) {
  case FDD:
    frame_type = "FDD";
    break;

  case TDD:
    frame_type = "FDD";
    break;
  }
----------------------------------------------------------