Support arch names in the buildcore revisions list (for if build_core is used), Unmount after buildcore cleanup, change permissions for the user on the file, and symlink the latest log directory to a fixed path

git-svn-id: svn://svn.code.sf.net/p/linuxrcd/code@212 3df0df1f-9518-46d5-b0fc-6e62cabb456f