Updating Backbone to 1.1.0, Underscore to 1.5.2 and some other fixes

- Upgraded backbone to `1.1.0` and underscore to `1.5.2`
- Fixed TodoMVC example
- Removed `examples/assets/` and added them as `devDependencies` in `bower.json`
- Fixed issue where certain events would not be bound if they were on the root `el` (see change to `viewRegistry.getEnclosingView` in `src/thumbs.core.js`)
- removed `src/thumbs.viewRegistry.js` since it is not referenced (we use the viewRegistry defined in `src/thumbs.core.js`
- setup travis ci

**Test**
`npm install`
`bower install`
`grunt test`

- [ ] @doug-martin 
- [ ] @andymoon 
- [ ] @jkc 
- [ ] @jvanwinkle 
- [ ] @achura