Configurable Column Order of Contracts #71

In the contract view, make the column ordering configurable. This could be through drag & drop or even just a (textual) number ordering in a configuration page.
I frequently use Sia Host Manager to compare values in columns and, often, those columns are at opposite ends of my screen (i.e. far left and far right). I would like to be able to have them side-by-side for easier comparison.