Support for Android API 10; isAttachedToWindow() workaround

Hi,
pretty cool library.
I want to use it in one of my projects. Unfortunately I have to support android 2.3.3 (API 10) in one of my projects wehere I want to use your library (RealTextView with min textsize). Therefore I have added support for API < 11 by using a workaround instead of `OnLayoutChangeListener` (available since API 11). The workaround is overriding `View.onSizeChanged()` and to call  `autofit()`. If API >= 11 then `OnLayoutChangeListener` will be used.

I also noticed that you use `isViewAttached()` to restart the animation.  This method was introduced with API 19. For previous API you have to use a workaround (implemented by me) by overriding `onAttachedToWindow()` and `onDetachedFromWindow()`.