openpgm: Add Pragmatic General Multicast library

OpenPGM is a library implementing the PGM reliable multicast
network protocol; The famous messaging library ZMQ has an
optional dependency on OpenPGM, with OpenPGM enabled, we can
foster the development of multicast network applications.

Signed-off-by: Ye Holmes <yeholmes@outlook.com>

libs/openpgm/patches/0001-Rename-openpgm-5.2.pc.in.patch

@@ -0,0 +1,45 @@
+From 240634b1afb968a051f8c68696eae2a582a02450 Mon Sep 17 00:00:00 2001
+From: Fabrice Fontaine <fontaine.fabrice@gmail.com>
+Date: Mon, 31 Aug 2020 20:16:25 +0200
+Subject: [PATCH 1/2] Rename openpgm-5.2.pc.in
+
+This will fix the following build failure:
+
+config.status: error: cannot find input file: `openpgm-5.3.pc.in'
+
+Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
+---
+ openpgm/pgm/{openpgm-5.2.pc.in => openpgm-5.3.pc.in} | 0
+ 1 file changed, 0 insertions(+), 0 deletions(-)
+ rename openpgm/pgm/{openpgm-5.2.pc.in => openpgm-5.3.pc.in} (100%)
+
+--- a/openpgm/pgm/openpgm-5.2.pc.in
++++ /dev/null
+@@ -1,12 +0,0 @@
+-prefix=@prefix@
+-exec_prefix=@exec_prefix@
+-libdir=@libdir@
+-includedir=@includedir@
+-
+-Name: OpenPGM
+-Description: PGM Protocol Library.
+-Version: @PACKAGE_VERSION@
+-# packagers may wish to move @LIBS@ to Libs.private for platforms with
+-# versions of pkg-config that support static linking.
+-Libs: -L${libdir} -lpgm @LIBS@
+-Cflags: -I${includedir}/pgm-@VERSION_MAJOR@.@VERSION_MINOR@
+--- /dev/null
++++ b/openpgm/pgm/openpgm-5.3.pc.in
+@@ -0,0 +1,12 @@
++prefix=@prefix@
++exec_prefix=@exec_prefix@
++libdir=@libdir@
++includedir=@includedir@
++
++Name: OpenPGM
++Description: PGM Protocol Library.
++Version: @PACKAGE_VERSION@
++# packagers may wish to move @LIBS@ to Libs.private for platforms with
++# versions of pkg-config that support static linking.
++Libs: -L${libdir} -lpgm @LIBS@
++Cflags: -I${includedir}/pgm-@VERSION_MAJOR@.@VERSION_MINOR@