The RBs were not marked as used. A later UE downlink scheduling
could use those RBs, messing up everything.

Not sure this is the right place to mark them used. Maybe better
to do it in the "if (!CCE_allocation_infeasible" test.

The old value was 6, it should be 8 because those fields are
casted to 'struct DCI0_5MHz_FDD' and the like and those have
a size multiple of 32 bits, that is 4 or 8 bytes as of today.

(MAX_DCI_SIZE_BITS is 45, all the shifts, muls and adds lead
to a value of 8 after this commit and 6 before.)

The problem manifested itself with a 20MHz eNB. Push the traffic,
after a while the DL harq process 0 is not used anymore.
This is because DLSCH_DCI is directly followed by nb_rb in
the structure UE_TEMPLATE and setting a value for harq process 7
did overwrite nb_rb[0], putting much too big values in there,
leading to the scheduler to always refuse to reschedule because
the required RBs are impossibly huge (I saw values of 32744, 16384,
and others).

The code was changing the rnti in the red-black tree without
removing/reinserting the context. This is wrong because the
rnti is a key of the red-black tree and you cannot change the
key in a stored item at will.

There are also modifications of the function mac_eNB_rrc_ul_failure
which has to remove the UE in any case.

And rrc_mac_remove_ue has been changed for the case where
the UE is not found.

adding two rules for run_enb_ue_virt_s1 script to resolve the issue of data path with simulated UE (contributed by A. Ksentini)

The distinction common space/user space still requires some
careful examination.

if you compile *without* T it fails because the T macro is interpreted
as a function call

removed some traces that flooded the screen. Added UE information in PHY/MAC/RRC to indicate status of active/failing UEs every 10.24 seconds.

changed threading (acqusition is slot based). removal of eNB_thread. timing all based on received timestamp.

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 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.

it was at the wrong place
it was also wrong (< instead of <=)

added Timing advance tracing to .vcd output. Increase maximum UL RB count to 45. Measured UL throughput @ 15 Mbit/s (40 PRBs).