draw using d3
visualize modules updates
Add drag and drop
move OR connect (see code)
connect using Command key
remove w and h
Merge branch 'master' into d3

+ Fix module id

Conflicts:
	app/assets/javascripts/models/module.js
	app/assets/javascripts/ui/nodeEditor.js
Bower: add d3, remove raphael
Merge pull request #16 from gre/d3

refactoring of the node editor with D3