tools: improve user experience by choosing best certificate
automatically and print final response in a pretty way

ndns-update
 - pick the best certificate to sign the Update automatically
 - support multiple token for content option

ndns-dig
 - enhance output option
 - change behavior of iterative query controller when NS query is NACKed

logger
 - set default logger output to std::cerr

Change-Id: Ib06981c224ccad2a122a4505c84a60977184a55b
diff --git a/log4cxx.properties.sample.in b/log4cxx.properties.sample.in
index 15a36d7..7b0185f 100644
--- a/log4cxx.properties.sample.in
+++ b/log4cxx.properties.sample.in
@@ -1,5 +1,6 @@
 log4j.rootLogger=TRACE, A1
 log4j.appender.A1=org.apache.log4j.ConsoleAppender
+log4j.appender.A1.target=System.err
 log4j.appender.A1.layout=org.apache.log4j.PatternLayout
 
 # Print the date in ISO 8601 format