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

develop_integration_w25 into develop

Summary of changes:
- UE: configurable thread
- UE: fix in dci format1c decoding
- bladeRF hack
- configuration files for oaisim

See merge request !209

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.

develop_integration_w24 into develop

Summary or changes:
- work on transmission mode 3 and 4

See merge request !204

only with XFORMS enabled.

The way it was done was confusing.
However, now rank adaptation (if enabled) is not visualized correctly.