1.0.3dev: Wrap email address next to CC checkbox in `label` so that it toggles the checkbox. Refs #10984, #11804.

Patch by Jun Omae.


git-svn-id: http://trac.edgewall.org/intertrac/log:/branches/1.0-stable@13364 af82e41b-90c4-0310-8c96-b1721e28e2e2