Working version with some stability questions

This version handles drag and dropped folders and files and generates
the processed dicom files as a zip file for download.

Issue remains that sometimes the xml2dcm process aborts.
Merge branch 'update-dcmjs' into gh-pages

* update-dcmjs:
  Update dcmjs.js based on commontk/dcmjs@3995ab2
Use correct memoryInitializerPrefixURL
Merge branch 'update-dcmjs' into gh-pages

* update-dcmjs:
  Use correct memoryInitializerPrefixURL

Conflicts:
	organize/index.html
Refactor code adding dcmjs.utils.execute(prog, arguments)
Merge branch 'refactor-dcmtk-program-calling' into gh-pages

* refactor-dcmtk-program-calling:
  Refactor code adding dcmjs.utils.execute(prog, arguments)