fix(inputs): ignoring input events in IE caused by placeholder changes

In `sniffer.js` and its spec, it is implied that it **does** implement `input` events, we just prefer to ignore them, becuase the implementation is _so fubared_. 
Either way (no implementation vs fubared&ignored) it probablt makes sense to add a comment here, so future "touchers" don't wonder: "Hm...did we miss IE9 here ?"