More stable performance of nfapi-L2-emulator with 2 UEs, after dealing with some PNF-VNF synchronization issues.

Fixed a bug. Now both UEs reaching RRC Connection Reconfiguration state about 90% of the executions. Less frequently appearing issues remain to be fixed.

Extension to multiple UEs. Currently being tested with two UEs. Second UE doesn't always reach the RRC Connection Reconfiguration stage.

Minor modifications. Some problem appears rarely that prevents the reception of RRCConnectionSetupComplete message at the eNB.

Merge with latest changes of LTE-D2D/master

PC5-U - passing (source,destination) down to PDCP/RLC/MAC (first alternative - mapping of L2Ids form IP Addresses

Summary of changes:
- noS1 fixes
- various bugs fixed

Seemed to have fixed pnf(UE) -vnf(eNB) sync issue. Works up to the reception of RRConnectionReconfigurationComplete message at the eNB but crashing after that.

Merge branch 'develop-nos1-fixes' of https://gitlab.eurecom.fr/oai/openairinterface5g into develop-nos1-fixes

Merge branch 'develop-nos1-fixes' of https://gitlab.eurecom.fr/oai/openairinterface5g into develop-nos1-fixes

Merge branch 'develop-nos1-fixes' of https://gitlab.eurecom.fr/oai/openairinterface5g into develop-nos1-fixes

Conflicts:
	cmake_targets/CMakeLists.txt
	openair1/SCHED/phy_procedures_lte_eNb.c
	openair2/RRC/LITE/rrc_UE.c
	openair2/RRC/LITE/rrc_common.c
	targets/SIMU/USER/oaisim_functions.c

Conflicts:
	cmake_targets/CMakeLists.txt
	openair1/PHY/LTE_TRANSPORT/dci_tools.c
	openair2/RRC/LITE/rrc_UE.c

Works up to the reception of HI_DCI0.request at the UE-PNF. Sometimes Msg3 arrives later than expected at the eNB-VNF.

Summary of changes:
- heavy code cleanup (#ifdef removal)
- bugfixes