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

...r focus/blur on inputs with placeholders

This is my attempt at fixing #8242 as well as the extra placeholder issues with focus/blur. I'm assuming I'm missing a weird test case that still breaks somewhere, but I still think this is an improvement (it definitely is for my use cases).
The plunker in #8242 shows otherwise...?

As I understand it the extra input event occurs when the placeholder visually changes. If it changes while not visible (because the input has focus or a value) it doesn't seem to occur.  All my tests have been in IE11, it is possible IE10 is different...