EQUALHEIGHT: change style property to minheight

* Changed ```height``` property setting to ```min-height``` to allows the container to grow so asynced children objects, img, etc can come in later and/or resize safety pushing the container it is in correctly since it is not restricted with the current fixed height.
* Corrects the text falling out of the container when text-size is increased by users, since it was setting the height, hence restricting the box from growing.
* It is IE8 safe, since a prior PR added the ```auto``` to the height attribute, which is in essence doing the same thing which allows the box the grow if needed.

Note: This fixes the current accessibility issues with presents itself by having the plugin add a value to the height property of the element which restricts any further growth of the element save triggering the resize() function. Using ```min-height``` offers the same functionality in terms of setting the baseline height of all boxes as children using min-height. To be more robust there will have to be some work done to explore triggering the resize() function as things come in.