Allow to specify package name in config files

change package name for 10.9 Mervericks:

       RubyCocoa-1.1.0-OSX10.9
    -> RubyCocoa-1.1.0-OSX10.9-Ruby1.8

git-svn-id: https://svn.code.sf.net/p/rubycocoa/svn/trunk/src@2587 f4f36d40-9719-0410-9868-dde021a23eda