For click to close, only return false if they click overlay.

If we return false, their click will hide the guider but not have any
other effect (e.g. it will not follow a link).

* return false corresponds to preventDefault and stopPropogation.
* If someone clicks on a greyed out area, they may not devote
attention to what they're clicking on.
* If it's fully visible, they generally will.

Change-Id: Ib5cfee82cf7761162c24b519ee38747240375204