Fix NOTICE file in the source distribution

jmclean kindly reported on the dev@ mailing lit that we should cite this files in the NOTICE file we distribute with the Source distribution

These BSD licensed files:
  ./zookeeper-client/zookeeper-client-c/src/hashtable/hashtable.c
  ./zookeeper-client/zookeeper-client-c/src/hashtable/hashtable.h
  ./zookeeper-client/zookeeper-client-c/src/hashtable/hashtable_itr.c
  ./zookeeper-client/zookeeper-client-c/src/hashtable/hashtable_itr.h
  ./zookeeper-client/zookeeper-client-c/src/hashtable/hashtable_private.h

This MIT licensed file:
./zookeeper-contrib/zookeeper-contrib-loggraph/src/main/resources/webapp/org/apache/zookeeper/graph/resources/date.format.js

This MIT licensed files:
./zookeeper-contrib/zookeeper-contrib-loggraph/src/main/resources/webapp/org/apache/zookeeper/graph/resources/g.bar.js
./zookeeper-contrib/zookeeper-contrib-loggraph/src/main/resources/webapp/org/apache/zookeeper/graph/resources/g.dot.js
  ./zookeeper-contrib/zookeeper-contrib-loggraph/src/main/resources/webapp/org/apache/zookeeper/graph/resources/g.line.js
  ./zookeeper-contrib/zookeeper-contrib-loggraph/src/main/resources/webapp/org/apache/zookeeper/graph/resources/g.pie.js
  ./zookeeper-contrib/zookeeper-contrib-loggraph/src/main/resources/webapp/org/apache/zookeeper/graph/resources/g.raphael.js

This MIT licensed file
  ./zookeeper-contrib/zookeeper-contrib-loggraph/src/main/resources/webapp/org/apache/zookeeper/graph/resources/raphael.js

This BSD licensed file:
./zookeeper-contrib/zookeeper-contrib-loggraph/src/main/resources/webapp/org/apache/zookeeper/graph/resources/yui-min.js

This Apache 2.0 licensed file:
./zookeeper-contrib/zookeeper-contrib-zooinspector/src/main/java/com/nitido/utils/toaster/Toaster.java

This MIT licensed file:
./zookeeper-docs/src/main/resources/markdown/skin/prototype.js

Please note that I may not have found all the 3rd party files in the source release.