Fix for masked TEXTAREA in IE8

Hi, 

Thank you for great piece of code that save my time. 

When I attached it to my code, my users which uses old IE8 reported that masked input doesn't work. I used your code to mask TEXTAREA. Surprising in IE8 maskedinput works with INPUT's, but breaks on TEXTAREA. I looked into your code and prepared a fix and IE8.Spec.js test case.  

Thanks, 
Filip