Add pkg-config file for libjackserver

(cherry picked from commit 4f90ba0)

common/wscript

@@ -515,3 +515,13 @@ def build(bld):
         CLIENTLIB=clientlib.target,
         SERVERLIB=serverlib.target,
     )
+    # process jackserver.pc.in -> jackserver.pc
+    bld(
+        features='subst_pc',
+        source='../jackserver.pc.in',
+        target='jackserver.pc',
+        install_path='${PKGCONFDIR}',
+        INCLUDEDIR=os.path.normpath(bld.env['PREFIX'] + '/include'),
+        CLIENTLIB=clientlib.target,
+        SERVERLIB=serverlib.target,
+    )

jackserver.pc.in

@@ -0,0 +1,11 @@
+prefix=@PREFIX@
+exec_prefix=@PREFIX@
+libdir=@LIBDIR@
+includedir=@INCLUDEDIR@
+jack_implementation=jack2
+
+Name: jackserver
+Description: the Jack Audio Connection Kit: a low-latency synchronous callback-based media server (libjackserver)
+Version: @JACK_VERSION@
+Libs: -L${libdir} -l@SERVERLIB@
+Cflags: -I${includedir}