BatchUploader: multiple improvements

• Add new javascript file with all functions related to form validation.

• Remove error checking from server side

• Add an intermediate page before metadata submission to confirm the actions to be taken. (fixes #603)

• Perform an upload simulation via bibupload() to check for errors.

• Removed custom authorization messages so that a link to login is provided when user is not authorized

• xmllint sanity check is now performed during bibupload simulation

• Upload priority fix

• Refactoring of document upload form. Fixes display of radio buttons for upload mode

• Adds auto version to the batchuploader JS file

• Fix when accessing /batchuploader/confirm directly in the browser