py-mercurial: install chg

chg is a C wrapper for hg command that uses the Mercurial command
server to reduce start-up overhead.

Index: Makefile
===================================================================
RCS file: /cvsroot/pkgsrc/devel/py-mercurial/Makefile,v
retrieving revision 1.29
diff -u -p -r1.29 Makefile
--- Makefile	21 May 2019 20:55:02 -0000	1.29
+++ Makefile	21 May 2019 21:35:10 -0000
@@ -23,6 +23,13 @@ INSTALLATION_DIRS+=	share/doc/mercurial
 
 .include "version.mk"
 
+post-build:
+	cd ${WRKSRC}/contrib/chg && \
+	    make \
+	    DESTDIR=${DESTDIR} \
+	    PREFIX=${PREFIX} \
+	    MANDIR=${PREFIX}/${PKGMANDIR}/man1
+
 # Known test failures:
 # test-logtoprocess
 # https://bz.mercurial-scm.org/show_bug.cgi?id=6143
@@ -32,6 +39,11 @@ do-test:
 	cd ${WRKSRC} && make tests PYTHON=${PYTHONBIN} TESTFLAGS=${_MAKE_JOBS:Q}
 
 post-install:
+	cd ${WRKSRC}/contrib/chg && \
+	    make install \
+	    DESTDIR=${DESTDIR} \
+	    PREFIX=${PREFIX} \
+	    MANDIR=${PREFIX}/${PKGMANDIR}/man1
 	${INSTALL_DATA} ${WRKSRC}/doc/*.1  ${DESTDIR}${PREFIX}/${PKGMANDIR}/man1
 	${INSTALL_DATA} ${WRKSRC}/doc/*.5  ${DESTDIR}${PREFIX}/${PKGMANDIR}/man5
 	${INSTALL_DATA} ${WRKSRC}/README.rst  \
Index: PLIST
===================================================================
RCS file: /cvsroot/pkgsrc/devel/py-mercurial/PLIST,v
retrieving revision 1.23
diff -u -p -r1.23 PLIST
--- PLIST	21 May 2019 20:55:02 -0000	1.23
+++ PLIST	21 May 2019 21:35:11 -0000
@@ -1,4 +1,5 @@
 @comment $NetBSD: PLIST,v 1.23 2019/05/21 20:55:02 wiz Exp $
+bin/chg
 bin/hg
 ${PYSITELIB}/hgdemandimport/__init__.py
 ${PYSITELIB}/hgdemandimport/__init__.pyc
@@ -1287,6 +1288,7 @@ ${PYSITELIB}/mercurial/worker.py
 ${PYSITELIB}/mercurial/worker.pyc
 ${PYSITELIB}/mercurial/worker.pyo
 ${PYSITELIB}/mercurial/zstd.so
+man/man1/chg.1
 man/man1/hg.1
 man/man5/hgignore.5
 man/man5/hgrc.5