In the UE, we wish to handle ^C in the UE to send a message before
terminating, so we allow custom wait handlers to implement such
functionality. Use itti_wait_tasks_unblock() to unblock
itti_wait_tasks_end().

Also, implement itti_wait_tasks_end() using semaphores, as signals are
not async-signal-safe (and therefore should not be used in a signal
handler).

1. Reverts GTPU_need_ITTI back to develop
2. Removed gdb helper and co files
3. Reverts changes to logging mechanism
4. Reverts changes to assert that were unnecessary
5. Reverts changes to VNF that occured from a bad merge
6. Removes unnecessary else() in gNB softmodem

These cppcheck errors are occuring in code
that is untouched by this merge request.

And CPU affinity.
Also, use mlockall to keep our memory from being swapped out.

This commit contains work done by Eurecom and by Benetel.

This change is to enable use of gprof which requires the process
call `exit` to write out the collected data.

The UE (lte-uesoftmodem) exits cleanly, but the eNB
(lte-softmodem) crashes as it tries to shut down...

Found by valgrind.