Add boost asio async connection

Add an async connection and example of usage. This
connection inherits the bus object and allows async
method calls using boost asio. Most of these concepts
are from boost-dbus.

Change-Id: I33b5349d543c9ff4b6ee1ce15346c709c052e1ae
Tested: Compiled and ran asio-example on bmc.
Signed-off-by: James Feist <james.feist@linux.intel.com>
diff --git a/configure.ac b/configure.ac
index c3d8554..753d04d 100644
--- a/configure.ac
+++ b/configure.ac
@@ -133,6 +133,10 @@
     AC_SUBST([OESDK_TESTCASE_FLAGS], [$testcase_flags])
 )
 
+AC_ARG_ENABLE([boost],
+    AS_HELP_STRING([--enable-boost], [Enable building with boost.]))
+AM_CONDITIONAL(BOOST, [test "x$enable_boost" = "xyes"])
+
 # Create configured output
 AC_CONFIG_FILES([Makefile test/Makefile tools/Makefile tools/setup.py])
 AC_CONFIG_FILES([example/Makefile])