Use grunt for automating tasks and as a build system.

## Changes
* `grunt jshint` for jshint. `npm test` also works.
* `grunt jscs` for jscs. `npm test` also works (not working currently due to a bug).
* `grunt compile`. For future use, will ship corresponding adapter for the platform.
* `grunt ship` to create corresponding zip files (for ex. `.crx` and `.xpi` etc. Currently configured for chrome only.