Widgets:
- Fix support for expanding (wide) widgets in the Inactive Widgets area.
- Remove resizing of the sidebars height.
- Stop removing unneeded "for" attributes from labels inside the widgets. Was a fix for IE6 odd behaviour.  

See #26117.
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git-svn-id: http://core.svn.wordpress.org/trunk@26182 1a063a9b-81f0-0310-95a4-ce76da25c4cd