IE9+, Safari iOS6, viewport units in calc() and other fixes/features.

I have added the following to the buggyfill: 
    - fixes IE9 and Safari native way of calculating viewport units differently inside of a frame. Without this buggyfill, IE9 will assume the 100vw and 100vh to be the width and height of the parent document’s viewport, while Safari for iOS will choose 1px (!!!!) for both.
    - fixes IE9's issue when calculate viewport units correctly when changing media-query breakpoints.
    - vmin support for IE9 (instead of vm, IE9's equivalent to vmin) and vmax support to IE9 and 10. (Note that this will only work when initializing with viewportUnitsBuggyfill.init({use_css_behavior_hack: true});)
    - the ability for viewport units to be used inside of calc() expressions in iOS Safari and IE9+, via the use of the content CSS property. This seems like a good compromise since content is only valid inside ::before and ::after rules (as a result, it is not recommended use this hack inside of these rules). (Note that this will only work when initializing with viewportUnitsBuggyfill.init({use_css_content_hack: true});)
     - support for viewport units inside of IE's filter property (a.k.a. Visual Filters).
     - added debounce initialization parameter, if it is desirable to not have IE9+ fire the polyfill so many times on a resize event.