Make bug-reporting address more configurable.

Based on a patch by Joseph S. Myers in
<http://mm.icann.org/pipermail/tz/2012-November/018452.html>.
* Makefile (BUGEMAIL): New macro.
(version.h, tzselect): Use it to define REPORT_BUGS_TO.
* tzselect.ksh (REPORT_BUGS_TO): New variable, used for --help.
* zdump.c, zic.c (usage): Use REPORT_BUGS_TO for --help.

Makefile

@@ -8,6 +8,9 @@ PACKAGE=	tzcode
 # Version numbers of the code and data distributions.
 VERSION=	2012j
 
+# Email address for bug reports.
+BUGEMAIL=	tz@iana.org
+
 # Change the line below for your time zone (after finding the zone you want in
 # the time zone files, or adding it to a time zone file).
 # Alternately, if you discover you've got the wrong time zone, you can just
@@ -344,7 +347,8 @@ INSTALL:	ALL install date.1
 
 version.h:
 		(echo 'static char const PKGVERSION[]="($(PACKAGE)) ";' && \
-		 echo 'static char const TZVERSION[]="$(VERSION)";') >$@
+		 echo 'static char const TZVERSION[]="$(VERSION)";' && \
+		 echo 'static char const REPORT_BUGS_TO[]="$(BUGEMAIL)";') >$@
 
 zdump:		$(TZDOBJS)
 		$(CC) -o $@ $(CFLAGS) $(LDFLAGS) $(TZDOBJS) $(LDLIBS)
@@ -396,6 +400,7 @@ tzselect:	tzselect.ksh
 			-e 's|#!/bin/bash|#!$(KSHELL)|g' \
 			-e 's|AWK=[^}]*|AWK=$(AWK)|g' \
 			-e 's|\(PKGVERSION\)=.*|\1='\''($(PACKAGE)) '\''|' \
+			-e 's|\(REPORT_BUGS_TO\)=.*|\1=$(BUGEMAIL)|' \
 			-e 's|TZDIR=[^}]*|TZDIR=$(TZDIR)|' \
 			-e 's|\(TZVERSION\)=.*|\1=$(VERSION)|' \
 			<$? >$@

tzselect.ksh

@@ -2,6 +2,7 @@
 
 PKGVERSION='(tzcode) '
 TZVERSION=see_Makefile
+REPORT_BUGS_TO=tz@iana.org
 
 # Ask the user about the time zone, and output the resulting TZ value to stdout.
 # Interact with the user via stderr and stdin.
@@ -44,7 +45,7 @@ if [ "$1" = "--help" ]; then
 Usage: tzselect
 Select a time zone interactively.
 
-Report bugs to tz@iana.org.
+Report bugs to $REPORT_BUGS_TO.
 EOF
     exit
 elif [ "$1" = "--version" ]; then

zdump.c

@@ -272,8 +272,8 @@ usage(FILE * const stream, const int status)
 	(void) fprintf(stream,
 _("%s: usage is %s [ --version ] [ --help ] [ -v ] [ -c [loyear,]hiyear ] zonename ...\n\
 \n\
-Report bugs to tz@iana.org.\n"),
-		       progname, progname);
+Report bugs to %s.\n"),
+		       progname, progname, REPORT_BUGS_TO);
 	exit(status);
 }
 

zic.c

@@ -426,8 +426,8 @@ usage(FILE *stream, int status)
 [ --version ] [ --help ] [ -v ] [ -l localtime ] [ -p posixrules ] \\\n\
 \t[ -d directory ] [ -L leapseconds ] [ -y yearistype ] [ filename ... ]\n\
 \n\
-Report bugs to tz@iana.org.\n"),
-		       progname, progname);
+Report bugs to %s.\n"),
+		       progname, progname, REPORT_BUGS_TO);
 	exit(status);
 }