biojs snippets in cytoscape

Hey this adds some of your examples to the BioJS registry (as snippets).

You can test this locally by using 

```
gulp browserify
npm run sniper
```

And open [http://localhost:9090/snippets](http://localhost:9090/snippets)

The BioJS registry runs browserify on all packages.
Then it displays the examples (aka snippets) with a server-side version of the biojs-sniper.
Settings for the snippets are set in the `package.json`.

Here is [an example](http://registry.biojs.net/client/#/detail/biojs-vis-msa) of how the output in the registry will look.