Remove QueueProgress from plupload namespace.

No point to have it public.
Add helper class Collection.

In some cases array and object are not convenient enough.
 Encapsulate file related logic (uploading, resizing, etc) inside plupload.File.

Prepare the code base for multiple simultaneous upload support.
Bind event listeners to plupload.File and propagate them onto plupload.Uploader.
QueueProgress is private now.
Add uploadFile() method, notion of active and pending uploads and adapt the surroundings to new logic.
By default plupload should upload one file at a time.
Add Catalan, Vietnamese language packs. Update Armenian and Albanian.
Collection: Do not increment length counter if an item with the specified key is already present.
Ignore sftp-config.json.
Port over all the changes, since the parallel-upload was branched.
Merge branch 'parallel-upload'

Conflicts:
	src/plupload.js
UI: Show extensions instead of thumbs when thumb view is selected, but thumbs themselves not requested.