Fixed sigma.kill issue
"verbose" setting

The verbose settings determine wether sigma can or cannot logs errors and warnings. I also updated the API candy with the setting "skipErrors" to make it work when WebGL is not supported.
Merge branch 'draft-v1.0.0' of github.com:jacomyal/sigma.js into draft-v1.0.0
Fixed random colors in ForceAtlas2 example
Added the sigma.plugins.animate plugin

This plugin provides a simple way to animate a sigma instance by interpolating some specified node properties.
Also added an basic example showing how it works.
added missing plugins in the Gruntfile
Fine tuning on touch + mouse events

Improved the bindEvents script and the touch captor a bit. It is supposed to have fixed the #166 issue, but it has not been tested yet.
Minor fix on touch captor

Restored e.preventDefault in touch move handlers.
Merge branch 'draft-v1.0.0' of https://github.com/jacomyal/sigma.js into draft-v1.0.0