JSHint: run from bash and with checkstyle magic.

* generic publishing macro using the Checkstyle Plugin
* JSHint is now run directly instead of via wmfgrunt
* The console outputs a link to the Jenkins violation report

Depends on Ie622ad86 (publisher.checkstyle).

Change-Id: Ib14a6a7ce76caa7d3f6e03d4f86b01595ac2a7d2