Add JSHint to Travis
Make JSHint task fail in CI environment
Tweak gulp jshint task for CI environment

See:
https://github.com/spenceralger/gulp-jshint/issues/28
One more try with Travis and JSHint
Make JSHint pass
Merge branch 'master' into jebeck/tideline-plugins

Conflicts:
	app/core/chartutil.js