Made get() statically invocable
execute() incorrectly relied on mysqli::next_result() as the condition for looping through result sets with multiple queries.  Now correctly uses mysqli::more_results if multiple queries were being executed.
setTimes() updated to properly set the time_edit_until* timestamps dependent on the new ORDER_EDITABLE_WINDOW configuration variable.
inEditWindow() updated to properly handle the magic editable timestamp of zero (meaning always editable).
Made most (all?) - lots - of functions statically callable.
Added new ORDER_EDITABLE_WINDOW directive.  Previously orders were editable for 24 hours.  This directive lets you set that window in minutes, or set to zero (default) for always editable.