Update spring, spring security and mysql connector libs

- Update spring security 3.2.0 RC2 to 3.2.0 stable (use stable release for security framework)
- Update spring 3.2.4 to 3.2.6 (spring security 3.2.0 stable depends on spring 3.2.6)
- Update mysql connector 5.1.26 to 5.1.28 (resolve rewriteBatchedStatements=true issue)