Bug 1020847 - Add handwriting IME for Simplified Chinese.

Created a new function `setDomElemViewTargetObject `, which looks like `setDomElemTargetObject `, it's only used for handwriting pad now, and in the future it will replace `setDomElemTargetObject ` function. Now, the relationship diagram looks like: DOM Element<=> target => view. DOM Element is in the view, so it's not necessary to get it through "target" and also we can get "target" through DOM Element in the view.