update guava to v18.0
update guava to v18.0

sstafford/gerrit-rest-java-client,vogellacompany/gerrit-rest-java-client,vogellacompany/gerrit-rest-java-client,uwolfer/gerrit-rest-java-client,sstafford/gerrit-rest-java-client,uwolfer/gerrit-rest-java-client