update the versions of SVNKit and Subclipse we bundle in Red Hat Central

We could consider updating the versions of SVNKit and Subclipse we bundle in Red Hat Central.

Currently we have:

• Subclipse 1.10.9 / clientadapter 1.10.3
• svnkit 1.8.10 (supports up to svn 1.8)

Latest:

• Subclipse 1.12
• svnkit 1.8.12 (supports up to svn 1.9 - http://svn.svnkit.com/repos/svnkit/tags/1.8.12/CHANGES.txt)

Reason to update: https://developer.jboss.org/message/961176?et=watches.email.thread#961176