Major addition to support DNS SRV resolution in PJSIP:
- added DNS asynchronous/caching resolver engine in
  PJLIB-UTIL (resolver.[hc])
- modified SIP resolver (sip_resolve.c) to properly
  perform DNS SRV/A resolution when DNS resolution is
  enabled.
- added dns_test.c in PJSIP-TEST for testing the SIP
  resolver.
- added nameserver configuration in PJSUA-LIB
- added "--nameserver" option in PJSUA.
- updated project/Makefiles and doxygen documentation.



git-svn-id: https://svn.pjsip.org/repos/pjproject/trunk@753 74dad513-b988-da41-8d7b-12977e46ad98
diff --git a/pjlib-util/build/Makefile b/pjlib-util/build/Makefile
index 3c7be4f..a5d8c92 100644
--- a/pjlib-util/build/Makefile
+++ b/pjlib-util/build/Makefile
@@ -26,7 +26,7 @@
 #
 export PJLIB_UTIL_SRCDIR = ../src/pjlib-util
 export PJLIB_UTIL_OBJS += $(OS_OBJS) $(M_OBJS) $(CC_OBJS) $(HOST_OBJS) \
-		errno.o dns.o dns_dump.o getopt.o md5.o \
+		errno.o dns.o dns_dump.o getopt.o md5.o resolver.o \
 		scanner.o stun.o string.o stun.o stun_client.o xml.o
 export PJLIB_UTIL_CFLAGS += $(_CFLAGS)