Conflicts:
	openair1/PHY/NR_UE_TRANSPORT/nr_dlsch_demodulation.c
	openair2/LAYER2/NR_MAC_UE/nr_ue_dci_configuration.c
	openair2/LAYER2/NR_MAC_UE/nr_ue_procedures.c

Integration branch 2020 week 30  

- MR 854 : NR_DCI_01  
- MR 857 : improve_ue_stability  
- MR 839 : mac-flexran-improvements

- DM-RS type {1,2} was wrongly assigned to {1,2} instead of {0,1}
- Num DM-RS CDM groups without data is now taken into account in mthread
  decoding function
- number of DM-RS CDM groups without data for format 1_0 according to 5.1.6.2
  3GPP TS 38.214 version 15.9.0 Release 15:
-- the UE shall assume the number of DM-RS CDM groups without data is:
-- 1 (CDM group 0) for the case of PDSCH with allocation duration of 2 symb
-- 2 (CDM group {0,1}) for all other cases.

- moved RRC structs checks and mac configuration to config_ue.c
- new implementation of DCI configuration according to 3GPP TS 38.331
  version 15.9.0 Release 15 and 3GPP TS 38.213 version 15.9.0 Release 15

Oai integration week29

See merge request oai/openairinterface5g!858

Use LFDS 7.0.0 Ringbuffer implementation to handle
* Slice Configuration
* UE slice association
which is then uploaded through MAC scheduling thread

Selects the UE with the highest CQI. If two UEs have the same CQI,
choses the one with highest number of bytes in RLC queue. Allocates as
many RBGs as possible, and potentially continues with the next UE.

Selects UE with highest coefficient. Allocates until there are no more
RBGs to allocate, or UE has no more data. In the latter case, continues
with the next UE (second-highest coefficient).

- Loop only to next UE instead of jumping multiple

- mark used RBGs in rbg_mask

- Only calculate number of RBs based on CQI when UE is selected, instead
of calculating for all UEs which might be unnecessary.

- When looping the list of UEs for RB allocation, remove UEs that have
no data anymore instead of skipping them.

The preprocessor pre-allocates a CCE. Thus, when arriving at the check
for the number of RBs for retransmission, it is too late to skip the UE.
Therefore, only print a warning.

The default schedulers allocate a correct amount of RBs for
retransmissions, therefore it is ok.