fixes #881 - ensure credentialed CORS requests are sent when requested for the delete file feature
#801 - support for XDomainRequest for delete file feature
#801 - comment typos
#801 - fix preflight calculation
handle XDR POST requests in test servlet
#801 - update readme
#801 - update server-side readme
#801 - additional code comments
#801 - prevent calls to setRequestHeader if XDR is used
#801 - links to blog post
Merge branch 'feature/delete-cors-no-preflight' into develop - #801