Core items.
* test/rss/rss-assertions.rb (assert_multiple_dublin_core): added
an assertion for testing multiple Dublin Core items.
* test/rss/test_maker_dc.rb (test_rss10_multiple): added a test
for making multiple Dublin Core items.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@8259 b2dd03c8-39d4-4d8f-98ff-823fe69b080e