With --fork, keep the main process' .rec file without node id in the filename
even when it's not the first node (that is, when --node is also specified with
a MIN greater than 1).
Exclude the portion of code with the fork() call in DJGPP builds (untested)
Report OpenMP thread count, after adjusting it for --fork if necessary
Wait for child processes before the main process terminates
Revised the check for when to show OpenMP info to be correct for more than just
cracking runs
Corrected --restore of --fork'ed sessions
Corrected the comment on the rationale behind rec_unlock().  The previous
analysis was erroneous.
Don't bother reporting interrupted wait()