issue #41 - added in droppable functionality and demo
update readme
renamed droppable parent
added the term active to methods and fixed demo
fixed up demos
fixed up demos
extended droppable logic: custom overlap function et.c
fixed js errors and built pep
cleaned up droppable advanced demo
fixes #42 - refactored placeObject() function
fixes #44 - refactored constrainToParent and constrainToWindow options in a single option: constrainTo
added ability to stop other pep objects on page along with demo
better handling for parent constraints
better object placement; abstract parent position and object placement into their own functions
fixed up droppable demos
fixed constrainto example
check if object already has relative parent
fixed test