Some of them might not be correctly handled.
I put /* TODO: XXX */ where I didn't know if
the fix was correct.

fixes for precoding (turning off if nb_antennas_tx=1), configuration files, timing advance with 3/4 sampling on 20 MHz, logging in MAC

bugfix for DCCH2/SRB2 in eNB_scheduler_dlsch.c, demultiplexing SIMD alignment issue in ulsch_decoding.c, IF5 fronthaul modification in lte-enb.c

tested with both EXMIMO and USRP. performance better than in master branch.

remove debugging traces from lte-enb.c and if4_tools.c. modulo 1024 bug on frame counter in lte-enb.c

frame synchronization mechanism and robustification of if4p5 packet handling for out-of-order asynchronous reception (PDLFFT)

debugging information in lte-enb, addition of external reference option in lte-softmodem and usrp_lib.cpp