Log Message:
nsd: Update to 4.3.1

Changelog:
8 April 2020: Wouter
	- Tag for 4.3.1rc2.

7 April 2020: Wouter
	- Merge #91 by gearnode: nsd-control-setup recreate certificates.
	  The '-r' option recreates certificates.  Without it it creates them
	  if they do not exist, and does not modify them otherwise.

6 April 2020: Wouter
	- Merge #90 by phicoh: O_CLOEXEC should be FD_CLOEXEC.
	- Merge #92 by tonysgi: Fix typo.

2 April 2020: Wouter
	- Tag for 4.3.1rc1.

1 April 2020: Wouter
	- Fix for whitespace in minimal responses test for FreeBSD.

25 March 2020: Wouter
	- Merge #86 from noloader: Use precious variables for GREP, EGREP,
	  SED, AWK, LEX and YACC.
	- For #86: Fix that programs loaded after CFLAGS and stuff is
	  set, specifically the compiler, so that it can work if it needs
	  special flags from that.  Fix that lex only needs to support -i
	  if actually defined, otherwise the output included in the source
	  tarball can be used.
	- Merge #72 from noloader: Increase Travis testing coverage

23 March 2020: Wouter
	- Fix unterminated ifdef in nsd.h.
	- Fix unknown u_long in util.c for Issue #80 .

20 March 2020: Wouter
	- Merge #83 from noloader: Fix GNU HURD sched_setaffinity compile.
	- Fix #82: print error when system does not have setaffinity.
	- Fix #80: NetBSD and implicit declaration of reallocarray.
	- Fix for #80: Fix reallocarray test to define before include.
	- Fix for #80: Define alternatives for IFNAMSIZ if it does not exist.

19 March 2020: Wouter
	- Fix #76: cpuid typedef for Hurd, DragonflyBSD compile.
	- Fix #75: configure test for sched_setaffinity, and use
	  cpuset_setaffinity otherwise.  Also test for presence of sysconf.
	- Fix #74: GNU Hurd fix cast from pointer to integer of different size.
	- Fix for #74, #75: cpuset test for header contents and provide code.
	- Fix #78: Fix SO_SETFIB error on FreeBSD.

18 March 2020: Wouter
	- Fix #70: error: 'fd_set' undeclared.
	- Fix #71: error: 'for' loop initial declaration used outside C99
	  mode.
	- Fix to move declarations out of for loops in event test too.
	- Fix to move declarations out of for loops in popen3 test too.
	- Another fix to move declaration out of for loop for event test.
	- Fix to move declarations out of for loops in cutest regex display.