Revert [23375] until we can get Media fixed to work with newer versions of Backbone. see #23262


git-svn-id: http://core.svn.wordpress.org/trunk@23390 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Add underscore and backbone to the do-not-deregister list of scripts.

props adamsilverstein.
see [23378]. see #22896.



git-svn-id: http://core.svn.wordpress.org/trunk@23391 1a063a9b-81f0-0310-95a4-ce76da25c4cd