Updated release notes for version 1.9.1.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/beanutils/trunk@1555941 13f79535-47bb-0310-9956-ffa450edef68
Updated properties in pom related to the release version.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/beanutils/trunk@1555942 13f79535-47bb-0310-9956-ffa450edef68