Merge of develop-nr into develop

January 2020 Release -- LTE-M improvements; CDRX Improvements; Experimental MBMS and MCE support

Add support for different PUSCH DMRS modes; Nr dlsch multi threading; Merging develop tag 2019.w51 to develop-nr; RedHat Entreprise 7.7 build support

Merging develop tag  into develop-nr; some cppcheck fixes and also compilation warnings removal; hotfix: fix value of MAX_MOBILES_PER_ENB; hotfix for the UHD thread priority

CDRX optimizations; eMBMS-Vicomtech Fed4fire: support for eNB

DL IP flow based on nr-PHY over LTE RAN stack. Supporting internal timer

Hotfix: CQI scheduling in TDD

DL IP flow based on nr-PHY over LTE RAN stack. Supporting internal timer

DL IP flow based on nr-PHY over LTE RAN stack. Disabling UL procedures.

Hotfix: CQI scheduling in TDD

DL IP flow based on nr-PHY over LTE RAN stack. Working with internal timer as well

DL IP flow based on nr-PHY over LTE RAN stack.

Bug fixes (trace pdu, rfsimulator); improved hack on multi-rru clean-up; CI-CD support at R2LAB Inria