Add controller-level blocking

NOTE: Version 1.0 causes a minor breaking change from 0.9.
The `default` key in the config file changes from
`whitelist` and `blacklist` to `allow` and `deny`.
With this new wording, it becomes more clear what `default` really means.

- Add controlloer additions extension for ApplicationController
  - Add enable_blacklist_and_deny_by_default controller filter
  - Allow filter to be applied to specific methods
  - Allow an array of IPs to be passed as an extra argument
- Update README re: use cases, filtering, examples, and features
- Update dependencies, add coveralls
- Add more flexible rack test app
- Add basic support controllers and filter implementation
  for testing controller additions
- Bump version