Added custom animations and custom width options

[kersten]

Hi there,

I've added some custom animation options. With this you can implement your own animations and not the default slideDown stuff.

Also I've added the option to set a custom width if you need to.

To get this stuff via bower I've added the components.json. I think you might add this by yourself: bower register backbone.bootstrap-modal git://github.com/powmedia/backbone.bootstrap-modal

Feel free to accept this or reject it. If rejected, please tell what I have to do to get this stuff into the plugin.

Greetings Kersten