Support LIBS like LDFLAGS.

- Add LIBS="${LIBS}" to MAKE_ENV and CONFIGURE_ENV.
- Add an option helper for LIBS.
- Adjust all ports that already use LIBS.  Also remove references to
  PTHREAD_CFLAGS and PTHREAD_LIBS while here.
- Some ports did not support having a LIBS environment variable and
  required additional patches.

Somewhat simplified a linker command line looks like:

${CC} ${src_LDFLAGS} ${LDFLAGS} ${src_LIBS} ${LIBS}

where src_LDFLAGS and src_LIBS are controlled by upstream and LDFLAGS and
LIBS can be controlled by us.  If possible -L and -l flags need to be
added to LIBS to make sure they appear after any -L and -l flags set by
upstream.  Many ports currently add -L${LOCALBASE}/lib to LDFLAGS but this
may appear too early on the command line causing installed libraries to
be linked in instead of freshly built ones.

Additional changes:
benchmarks/netio: Replace WITH_IPV6 with an IPV6 option.
comms/gnokii: Replace some patches with USES=pathfix.  Also remove -fPIC.
graphics/gimageview: USES=libtool and install desktop file in DESKTOPDIR.
graphics/visionworkbench: Remove FreeBSD 7 support.
multimedia/libmovtar: New LIB_DEPENDS syntax.
multimedia/opencinematools: Use standard do-build.
net/siproxd: USES=libtool:keepla (port actually needs .la files for plugins)
net-mgmt/nagios: Remove -fPIC.
net-mgmt/nagios4: Remove -fPIC.
print/cups-base: Only add -lssp_nonshared on i386 and OSVERSION < 1000036.
security/p11-kit: Replace PTHREAD_LIBS in CONFIGURE_ENV with
ac_cv_func_pthread_mutexattr_init=no in CONFIGURE_ARGS.  This skips a test
in configure that falsely detects pthread_mutexattr_init in our libc.
sysutils/dar: Fix iconv detection.
x11/rxvt-unicode: Remove -lstdc++ and patch configure to remove a FreeBSD
hack and use $CXX as linker as on other platforms.

PR:		190592
Exp-run by:	antoine
Approved by:	portmgr (antoine)

3 files changed, 2 insertions, 4 deletions

diff --git a/converters/fix-mime-charset/Makefile b/converters/fix-mime-charset/Makefile
index 1f678d11cf65..2b3ad4bfd193 100644
--- a/converters/fix-mime-charset/Makefile
+++ b/converters/fix-mime-charset/Makefile
@@ -20,8 +20,8 @@ GNU_CONFIGURE=	yes
 USES=		perl5
 USE_PERL5=	build
 
-CONFIGURE_ENV=	LIBS="-L${LOCALBASE}/lib"
 CPPFLAGS+=	-I${LOCALBASE}/include
+LIBS+=		-L${LOCALBASE}/lib
 
 PLIST_FILES=	bin/fix-mime-charset \
 		man/man1/fix-mime-charset.1.gz
diff --git a/converters/pdf2djvu/Makefile b/converters/pdf2djvu/Makefile
index c964d193f13d..14ed2a1db1b3 100644
--- a/converters/pdf2djvu/Makefile
+++ b/converters/pdf2djvu/Makefile
@@ -18,8 +18,6 @@ LIB_DEPENDS=	libpoppler.so:${PORTSDIR}/graphics/poppler \
 		libdjvulibre.so:${PORTSDIR}/graphics/djvulibre
 
 GNU_CONFIGURE=	yes
-CONFIGURE_ENV=	LIBS=-pthread
-CPPFLAGS+=	-I${LOCALBASE}/include
 USES=		compiler:c++11-lang gmake pkgconfig
 
 PLIST_FILES=	bin/pdf2djvu man/man1/pdf2djvu.1.gz
diff --git a/converters/rcctools/Makefile b/converters/rcctools/Makefile
index 1706fdea8a5d..8441e79c60ba 100644
--- a/converters/rcctools/Makefile
+++ b/converters/rcctools/Makefile
@@ -15,8 +15,8 @@ LIB_DEPENDS=	librcc.so:${PORTSDIR}/devel/librcc
 USE_BZIP2=	yes
 GNU_CONFIGURE=	yes
 
-CONFIGURE_ENV=	LIBS="-L${LOCALBASE}/lib"
 CPPFLAGS+=	-I${LOCALBASE}/include
+LIBS+=		-L${LOCALBASE}/lib
 
 PLIST_FILES=	bin/rcc-recode