Run `grunt jshint` as a sanity check before release

The default Grunt task will run `jshint` on `Gruntfile.js`, `bower.json`, `package.json` and the contents of `src/`, but I've split the meta files from the library into a separate target because `pym.js` doesn't pass inspection with the default options. Tweak to suit.
Merge branch 'adding-gruntfile' of https://github.com/al-the-x/pym.js into al-the-x-adding-gruntfile
Cleanup jshint errors.
Move jsdoc to grunt task.