Miscellaneous improvements and cleanup

- Live reload on any HBS modification.
- Swapped out grunt-template-html for grunt-compile-handlebars for Handlebars helpers support.
- Added examples for using helpers and passing data into templates (partials included).
- Target multiple HBS templates for compilation.
- Cleaned up packages and tasks in package.json and Gruntfile respectively.
- Include some troubleshooting tips I ran into during installation.