coffee option fix, dry code, cleaner GF output, JS watch

- Don't create JS files when --coffee is chosen
- JSHint and livereload JS in serve mode
- DRY up index.js a bit
- Get rid of trailing whitespace in generated Gruntfile.js

Fixes #200
BREAKING CHANGE: When choosing --coffee, JS files will no longer be
created automatically as well.
Merge pull request #213 from eddiemonge/nojs

coffee option fix, dry code, cleaner GF output, JS watch