adding ability to pass options to forceatlas
Fixed #220: WebGL edges batch rendering fixed

Restored two different canvases for the WebGL renderer when edges are rendered per batches.
Merge remote-tracking branch 'origin/pr/215'
Fixed #175: Disable setAutoSettings in ForceAtlas2

It is now possible to skip the setAutoSettings call while starting ForceAtlas2, by just settings the parameter "autoSettings" to false.