SMP-16 Upgrade dependencies to allow threadsafe builds.

Although the sakai maven plugin had been marked as threadsafe, it's dependencies weren't marked as threadsafe which was causing a warning to still be issued when doing the build.

git-svn-id: https://source.sakaiproject.org/svn/maven2/trunk@123943 66ffb92e-73f9-0310-93c1-f5514f145a0a