Fix
Updated Facebook code to comply with Facebook's new API changes (see Facebook Platform Upgrade Guide). This fixes a problem in which clicking on the Like button would not display the Facebook pop-up/dialog and instead incorrectly replaced the Like button with a "confirm" link or text field with the caption "Say something...".
Important if you've copied and pasted the CSS from the README then please change your styling to the updated styling here. The old styling set a max-height for iframe and set overflow:hidden for divs which makes the Facebook pop-up fail to appear.
For more information on the reason behind this release see this issue. Thanks to James Huang @jamesy829 for finding this bug.