added x and y parameters to hello world example for helpless newbies like me :)
Faster implementation for dropping nodes in big graphs.
Merge pull request #44 from edsu/master

x and y in hello world example
Merge branch 'faster-drop-node' of https://github.com/tjdett/sigma.js into tjdett-faster-drop-node

* 'faster-drop-node' of https://github.com/tjdett/sigma.js:
  Faster implementation for dropping nodes in big graphs.
Merge remote-tracking branch 'upstream/master'