UI: Add form fileds only once on UploadComplete. Address #830.
UI: Add form fileds only once on UploadComplete. Address #830.

Historically filelist was rebuilt on every change in queue, be it new
file or file status change, so the form fields were automatically
always correct. Now that we do not redraw the filelist now and then, we
have to do it manually and properly.

envato/plupload,vitr/fend005-plupload,vitr/fend005-plupload,moxiecode/plupload,moxiecode/plupload,envato/plupload