Refactored several variables and aliases for readability.
Refactored several variables and aliases for readability.

This update provides improvements in code readability for several of the
more complicated functions, including getHtmlPlacement(),
getSvgPlacement(), and computePlacementCoords().

erthalion/jquery-powertip,jasco/jquery-powertip,stevenbenner/jquery-powertip,erthalion/jquery-powertip,stevenbenner/jquery-powertip,jasco/jquery-powertip