Fixed some more issues for running with multiple UEs. Added configuration option for the number of UEs.

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

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

fixes after merge with develop. Partial UE/eNB separation in build to avoid problems with NFAPI in oaisim UE/RRU.
tested with simulator.

This commit fixes issues introduced by the previous commit.

Summary of work:
- cleanup:
  - fix LOG_XX to be less verbose
  - fix cmake_targets/CMakeLists.txt
  - fix oaienv
  - remove dead code
- bug fixes:
  - in openair1/SCHED/fapi_l1.c we had:
      eNB->pdcch_vars[subframe&1].num_dci           = number_dci;
    should be:
      eNB->pdcch_vars[subframe&1].num_dci           = 0;
    This bug let the PHY send more DCIs than what should have been
    sent because num_dci is incremented later on in the code.
    This fix may be a problem for fapi mode, to be checked.
  - add new T VCD traces
  - revert openair1/PHY/TOOLS/file_output.c to 'develop' version
  - remove thread_id in logRecord/logRecord_mt
  - revert (and adapt) configuration files
  - be careful when doing frame++, we need to % 1024
  - revert target_rx_power in openair2/LAYER2/MAC/eNB_scheduler_ulsch.c
- NFAPI:
  - the open-nFAPI code has been included in the repository. See nfapi/README.
    Maybe we should "git clone" the Cisco repository instead. We have to be
    careful of availability though.

What has been tested:
- monolithic eNB FDD 5/10MHz with one UE, iperf UDP/TCP uplink/downlink

Anything else may fail to work, especially the FAPI mode, which has not
been tested at all.

It has been chosen to not include the full history of commits
from David. He included a binary version of wireshark, probably
a modified one that understands NFAPI. Wireshark is released under
the GPL license, we cannot include it in the repository. We could
have done a next commit to remove this binary. But then it would
still be present in the history of commits, which may not be allowed.
And it would take space on disk. We could edit the history to remove
wireshark entirely. But this operation is too complicated.

There was also a pcap capture file, which has nothing to do in
the history of commits and would take space on disk. There again,
it's too difficult to edit the history to remove it.

There was a file .gitignore that was also removed.

The original history can be found on David's repository:
https://gitlab.eurecom.fr/daveprice/openairinterface5g/
The branch is: nfapi-ru-rau-split.

A copy of that branch has been included in the internal OAI
repository, for those who have access to it.
The branch is the same. The last commit ID is
9106438239e0bc626ff1fa1d97d911caadd0fbb9.

You can compare the current commit with the commit 9106...
to see what differs.

The current commit has to be considered non-working.
The commit following the current commit will fix problems with
the work in the current commit.

If you use git bisect, don't spend time analyzing the current
commit.

changing of notation for Random-Access procedure to match documentation. Function remains the same. Indentation (-kr) run on all files in LAYER2/MAC

uplink data from ue received, corrected scheduling of DCI0/UPLINK_CFG.  Fails to correctly form (SFNSF) for PHICH ACK

Change +4 for tx to a variable and get it to run at +2, this alllows nFAPI to get the reply back for HI_DCI0 to generate the PHICH in time

Crashes around msg4 time, but understand that need to get the ACK for the UE UL of msg3 back to UE within 4ms

- re-use ta_timer
- when ta_timer is running:
  - no TA sent to UE
  - no TA from UE (for UE to have time to apply previous TA command)
- decrease ta_timer every TTI
- be careful to use correct value of ta_update (31 means no TA)

Maybe not correct, to be checked.

RACH received on VNF.  Message 2 created and sent to PNF.  Got Message 2 received on PNF.  Nothing useful done with it yet

handling of PDCCH order. stoping UE-specific scheduler during RA procedure. checking for DCI format (resource allocation) to not overwrite resource_block_coding for format 1A DCIs.

put 50 PRB back in default enb configuration. added handling of UE release in L1/L2. detection of stale ULSCH configuration

NFAPI RACH now working.  Gets sent to VNF.  VNF cores currently on receipt.  Probably fixed by merge from main RU-RAU-split which I will do next

fixed various bugs in NFAPI interface and DCI CCE allocations (eNB_scheduler_primitives.c:allocate_CCEs())

fixed coherency issue across slots for PUCCH 1A/B detection (energy detection component). Introduced a variable scaling for channel matched filter in PUCCH1A/B detector. Current version goes as far on simulator as RU-RAU-split prior to merge with develop

addition of MPDCCH format 5. X_u_br sequences for BL/CE UE support and bugfixes in rx_prach0 for eMTC.

complete programming of Msg2/Msg4 procedures for eMTC. Addition of skeleton for PUCCH UCI (NFAPI) in L1. Some cleanup of eNB_scheduler.c