Fix NFAPI integration

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.

targets/COMMON/create_tasks.c

@@ -42,7 +42,7 @@
 
 int create_tasks(uint32_t enb_nb, uint32_t ue_nb)
 {
-  LOG_E(ENB_APP, "%s(enb_nb:%d ue_nb:%d)\n", __FUNCTION__, enb_nb, ue_nb);
+  LOG_D(ENB_APP, "%s(enb_nb:%d ue_nb:%d)\n", __FUNCTION__, enb_nb, ue_nb);
 
   itti_wait_ready(1);
   if (itti_create_task (TASK_L2L1, l2l1_task, NULL) < 0) {