removed minor AVX2 optimizations from 16-bit turbo decoder. had issues for small block lengths in UE.

bugfixing for UL. Remaining problems: CCE allocations in subframe 5 lead to occasional illegal DCI allocations (affects UL DCI which is missed by UE). waveform compliance with CQI in ULSCH.

added a new check for illegal file permissions to mbmssim.c, to avoid a segfault if permissions are invalid.

added hotfix for DCCH bad size limitation (to be checked after merge with develop).  Changed UL idle scheduling to improve 5MHz performance, changed DCI aggregation for ue-specific DCIs (reduces contention with SI and RA in subframe 5 for 5 MHz). Added RRC timer for UE release which cleans L1.  Still issues in 10 MHz throughput with TCP. 5 MHz seems almost fine.

changes in BSR handling in eNodeB. UL throughput on 5 MHz is 8 Mbit/s (mcs 19, 20 PRB). MCS 20 is not working for an unknown reason.

modifications in UE NAS to allow OAI UE to connect to. Note this is hard-coded in NAS, it will no longer work with openairCN.  To be fixed before merging into develop branch
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fixed mbmssim compilation issue
one more fix for build script sudo usage