Refactored pie and provided general clean up

core.js
* Added dynamicLeftPadding option which will use the width of the
  labels on the y axis to determine the correct amount of padding so
  the graph doesn’t obscure the label text.
* Added precision option to allow for manually specifying a default
  precision for graphs.
* Created helper method (animateJQP) that will animate a Raphael object
  using standard parameters but returns a jQuery promise that resolves
  when the animation is complete.

pie.js
* Mouse events are now disabled during load and rotation animations.
* Provided ability to use html to provide labeling.  Previously Raphael
  draw() was being used to generate VML/SVG for labels; as a result,
  the labeling was highly inflexible.
* Refactored Elroi to better utilize jQuery.
* Added logic to keep track of the true paths of wedges after rotation.
  This is essential for hit detection as Raphael has a bug in its
  isPointInside() method.

Additional Notes
* Split changes to elroi.js back into the corresponding files in lib.
* Removed astroSpinningPie examples.