refactor makeSource and makeTarget to centralise the data members they use, in preparation for extracing to a separate script
source and target endpoints reset correctly
fixes #153
final fixes #143
fix for yui and mootools getting position of dragged element
add some comments about possible enhancement to drag stuff
fixes #164 - attempt to reuse dead endpoint by makeSource or makeTarget configured with uniqueEndpoint set to true
update makeTarget drop code to fix #157 connectionMoved event not fired