util, transport: add configuration file support and make default unix socket configurable

add sample library configuration file

refs: #1364

Change-Id: I3cb36d078aa3f0b0a50d9a83a521e95448df0a93
diff --git a/wscript b/wscript
index 76d9ce7..d23de94 100644
--- a/wscript
+++ b/wscript
@@ -125,6 +125,8 @@
 
     conf.load("coverage")
 
+    conf.define('SYSCONFDIR', conf.env['SYSCONFDIR'])
+
     conf.write_config_header('src/ndn-cpp-config.h', define_prefix='NDN_CPP_')
 
 def build (bld):
@@ -209,6 +211,8 @@
 
     bld.install_files("%s/ndn-cpp-dev" % bld.env['INCLUDEDIR'], bld.path.find_resource('src/ndn-cpp-config.h'))
 
+    bld.install_files("${SYSCONFDIR}/ndn", "client.conf.sample")
+
 @Configure.conf
 def add_supported_cxxflags(self, cxxflags):
     """