Remove Target Enforcement from MouseAdapter

Problem
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The MouseAdapter wouldn't handle wheel events if the target of the event was a child of the element the handler was registered for.

Solution
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Remove the restriction.

Unit Tests
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Updated

How To +10/QA
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- Travis CI build should pass.

@lancefisher-wf @robbecker-wf @patkujawa-wf @georgelesica-wf @tomconnell-wf @todbachman-wf