Add meteor.js packaging

In an effort from the Meteor.js community to try and keep wrapped packages to a minimum we are trying to get support for meteor packages into the official repositories.

This PR provides an easy way to publish your plugin as a meteor package, making my wrapper package unnecessary. =)

What's needed from you part is to go to http://meteor.com and register for a developer account.

If you don't want to use mouse0270 as your username then choose another one but you will need to update [THIS line](/zimme/bootstrap-growl/blob/meteor-integration/meteor/package.js#L2) to match the namespace which is your username or an organization.

If you want to use some organization to publish under like 'remabledesigns' then you can create the organization from the settings
of your developer account at meteor.com, also don't forget to change the packageName to 'remabledesigns:bootstrap-growl' in case you
go that route (see above link).

'namespace:packagename' is the naming convention of meteor packages, to give credit to authors/organizations and to try and minimize conflicts. Choose namespace and package name carefully as there currently isn't a way to change names without publishing a new package.
This will confuse people unnecessarily.

If anything is unclear don't hesitate to ask.

Thank you for the great work you do with this package =)