Added static assets for displaying an AJAX loading page.
Merge pull request #4 from nathan-osman/loading-ui

Added static assets for displaying an AJAX loading page.
Configuration now works sensibly.

* Command line args possible to do complete setup
* All default values used.
* Command line overrides JSON config file.
Improved documentation.
API visibility and documentation changes.
Update README.md
Add a way to find resource dir

Make it possible to find the resource directory via a search path or
passing it via configuration options.
Add stager check API

Make it possible to handle the loading page and all of that jazz
Show the loading template for stager