Fix pass by reference issue. see #24873.

Merges [24865] to the 3.6 branch.



git-svn-id: https://core.svn.wordpress.org/branches/3.6@24867 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Unique load array in load-scripts and load-styles. Merges [24868] to 3.6.



git-svn-id: https://core.svn.wordpress.org/branches/3.6@24869 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Limit pingback response size. fixes #4137.



git-svn-id: https://core.svn.wordpress.org/branches/3.6@24870 1a063a9b-81f0-0310-95a4-ce76da25c4cd