Added test framework and basic tests about platform support
- Added Buster.JS and integration in Grunt
- Refactored window/navigator specifics out into dediacted classes
- Extracted two notions: update strategies and browser platforms
- public interface remained intact
Added end-to-end tests for button mappings of existing devices
- These will help for the API change to unify the button names
- Extended index.html to also show the raw, unmapped values
refined mapping tests to include negative axis values (logitech case)
Merge pull request #14 from dertseha/test-framework

Added test framework, refactored platform (browser) support to make it testable