I should be able to create and download a text file

(User Story, To be Fixed , Priority: High, Test Status: No automated tests yet , Reported By Justin du Coeur, )
Client
Summary: Needed for the Arisia Use Case, for the interim before we have a proper export API. We should be able to press a button and download the current jobs data.
I need to figure out how to initiate a download from a display button; this surely can't be hard.
For purposes of this story, the download wants to be arbitrary text. Basically, I should be able to specify the contents as a QLText, which is probably the parameter to the new _downloadButton() function. But the actual contents should not be generated until the button is pressed, so it may want to be activated by a _QLButton instead.