Bootstrap 3 templates

I added a new `bootstrap3.html` that includes new template files, screenshots below.


![screen shot 2013-10-14 at 8 01 50 pm](https://f.cloud.github.com/assets/455026/1330441/09083b6c-352d-11e3-962b-e93d72620513.png)
![screen shot 2013-10-14 at 7 46 02 pm](https://f.cloud.github.com/assets/455026/1330386/b6497bf8-352b-11e3-8461-f4f796f672d4.png)
![screen shot 2013-10-14 at 7 47 32 pm](https://f.cloud.github.com/assets/455026/1330387/b79ca2aa-352b-11e3-9f2c-a5c125d3913f.png)

Validation Error
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![screen shot 2013-10-14 at 7 55 41 pm](https://f.cloud.github.com/assets/455026/1330406/2b286132-352c-11e3-9cca-c762a160a518.png)


To support bootstrap - atomic Editor els `<input>, <select>` all need `.form-control` - so the ability to specify one in template JS via `Form.Editor.baseClassName = 'form-control';` was needed.  Several classnames are added in the complex fields that do not delegate to templates (radio, checkbox) - If a PR that moves these to use templates is desired first I can do that.  In addition, I expanded on the capabilities of Form options i propsed here https://github.com/powmedia/backbone-forms/pull/303  to allow the field `errorClassName` to be specified, it seems I cannot do that without making my own field subclass; this seems like alot of work for a common tweak.