Upgrade Spring dependency to 3.2.5.RELEASE

A vulnerability was found in the Spring framework: http://seclists.org/fulldisclosure/2013/Nov/31

This has no direct impact on our stack since both affected modules (Spring MVC and OXM) are not used/packaged by vanilla HST2, but as the impact of upgrading to the latest v3.2.4 of Spring is probably minimal we would like implementations of the HST to use these modules with the latest, secure release of Spring.

More info:

• http://www.gopivotal.com/security/cve-2013-4152
• https://jira.springsource.org/browse/SPR-10806