Supporting multiple file upload runtimes with pupload inside ExtJS 4

The reference client I built for FolderGrid's API is a zero footprint web client created using ExtJS 4. I wanted to support drag & drop file uploads for advanced browsers but degrade nicely all the way back to IE6 for those poor lost souls stuck with tech from the last decade. So I integrated plupload and bound the two together with some jquery glue.

The results are working well in production and the client itself is open & licensed under GPL v3 per the terms of ExtJS 4. So if you are interested in copying & extending - have at it.