Performance Fix for File Proxy. Ued ContentStream instead of ContentFile so that there is not need to write the stream to File before upload.
Change to add Content type header as well as correct content type in Content Stream
corrected compilation issue
Merge pull request #1079 from VineetKanwal1/FileProxyPerformanceFix

Performance Fix for File Proxy. Used ContentStream instead of ContentFile so that there is not need to write the stream to File before upload.