Renumber cluase 4 to 3, per what everybody else did when BSD granted
them permission to remove clause 3. My insistance on keeping the same
numbering for legal reasons is too pedantic, so give up on that point.
Submitted by: Jan Schaumann <jschauma@stevens.edu>
Pull Request: https://github.com/freebsd/freebsd/pull/96
fopen(3) returns NULL in case it can't open the STREAM.
fgetln(3) returns NULL if it can't get a line from a STREAM.
malloc returns NULL if it can't allocate memory.
