minor R package build fixes for upcoming rdyncall 0.8.0

git-svn-id: http://dyncall.org/svn/dyncall/trunk@1634 c71cb566-5a31-4692-9165-cf76bdc42cab
updated ChangeLog

git-svn-id: http://dyncall.org/svn/dyncall/trunk@1635 c71cb566-5a31-4692-9165-cf76bdc42cab