make jshint config available outside of grunt

I mostly just needed this for syntastic, but the Gruntfile was failing its own
jshint so I updated it too.
test suite won't run without grunt

...so in my book that makes it a devDependency.

It changes too frequently to be workable as global package
anyway, so just ignore the warning.
Merge pull request #178 from wenzowski/feature/jshint

make jshint config available outside of grunt
Merge pull request #179 from wenzowski/feature/travis

test suite won't run without grunt