Added model annotations with the annotate gem.
Also edited Gemfile to specify the version used for some gems.
Renamed a couple of methods, maybe something breaks... I'm tired...
Fixed bad link for add/edit yields at the show variation view.
Added a script to download the production database into the local development db
Improved the mining spreadsheet

All columns can be used to sort the table. If none is used it defaults
to sort by id.
Also the refining gain percentage appears in red when it's a loss.
Added routes to doc/routes.txt for easier reference.
Added home page and a controller for future "static" pages