Log Message:
20171017
	+ add Debian compile/link flags to test-package.
	+ cleanup spurious warnings from latest gcc.
	+ changes for Original-Mawk #48:
	  + add checks for stack overflow and underflow
	  + increase stack limit to 1024
	+ updated configure macros
	+ update config.guess and config.sub

20161120
	+ add runtime check for assignments to OFMT and CONVFMT to ensure
	  they use a single parameter (Original-Mawk #47).
	+ repair build for --with-valgrind, broken in 20160930 const-fixes.

20161107
	+ correct sign-extension from 20160615 change to rand() (report by
	  Christian Neukirchen).

20160930
	+ optimize closes on regular expressions to filter out redundant
	  wildcards, fixing a special case leftover by changes in 20100224
	  (Original-Mawk #34).
	+ add regular-expressions to the -Wdump option when using mawk's
	  built-in regular expressions.
	+ fix a sign-extension in character-class parser (Original-Mawk #46).
	+ minor optimizations.
	+ improve use of const in tables.

20160927
	+ allow single-quote as a flag in printf, to complete the change
	  for LC_NUMERIC in 20121129 (report by Graham Monteith).
	+ revert one of the fixes made for a Coverity warning about loss of
	  precision in 20121209, which unnecessarily exposed a different
	  problem (Original-Mawk #45).

20160918
	+ simplify "system()" function by calling C "system()" \ 
function, and
	  use POSIX macros for wait-status to provide a less-ambiguous return
	  value (suggested by Aharon Robbins).
	+ add a null-pointer check in bi_mktime (patch by Ismael Luceno).

20160905
	+ escape '/' in range for test/reg4.awk to allow test-comparison with
	  gawk and BWK.
	+ updated configure macros, e.g., for compiler warnings and static
	  analysis:
	  + CF_CC_ENV_FLAGS
	  + CF_GNU_SOURCE
	  + CF_PROG_LINT
	  + CF_RAND
	  + CF_XOPEN_SOURCE
	+ minor build-fix for HPUX 11.11 "make", which is confused by the
	  recursive use of "make" in clean/distclean rules.
	+ amend fix for Gentoo #424137 to eliminate a memory leak when opening
	  files (Original-Mawk #44).
	+ update config.guess and config.sub

20160615
	+ correct range when using system rand() function, which was 0..2
	  rather than 0..1 on BSD systems (report/patch by Masaki Waga).

20160313
	+ correct order of checks for machine state in REtest which caused an
	  out-of-bounds reference (Original-Mawk #36).

20160226
	+ update COPYING from
	  https://www.gnu.org/licenses/old-licenses/gpl-2.0.txt
	  (Original-Mawk #38).
	+ minor updates to configure script macros
	+ update config.guess and config.sub