Conflicts:
	cmake_targets/build_oai
	openair1/PHY/LTE_TRANSPORT/prach.c
	openair1/SCHED/phy_procedures_lte_ue.c
	targets/ARCH/COMMON/common_lib.h
	targets/RT/USER/lte-softmodem.c

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

The one in lte-enb.c disrupts the realtime. Using a B200mini with
20MHz bandwidth leads to the UE unable to connect for it seesms like
the UL and DL are not properly time synched because of this sleep
of one second that happens after the USRP streaming has started.
We see some random access attempts but the decoded preamble is
wrong.

This may be dependant on the setup. I had sporadic errors with
a B210, where sometimes the UE could connect and sometimes not.

the functions are meant to restart the lte-softmodem (lower layers) and are not
supported in oaisim. They are provided to make oaisim compile.

I tried to change rx and tx attenuation by the config file, but they are not changed. The bug is because att_rx and att_tx do not put in RC.rru when local_rf is "yes" in config file. We need to put att_rx and att_rx for both local_rf = "yes" and "no". Also RF config which send to RF device must be fill by this parameters.

'_' is not a valid character.

S1AP specs say:

    ENBname ::= PrintableString (SIZE (1..150,...))

And X.680 (08/2015) 41.4 table 10 lists the valid characters for
PrintableString. '_' is not there. We replace by '-' which is there.

Connection of eNB to ppenair-cn has not been tested. There is no reason
why it would fail.