Enhance memory management and error handling in attachment processing#270

KoblerS merged 7 commits intomaincap-js/attachments:mainfrom

263-version-222-server-crashes-with-oom-during-file-upload-and-virus-scanningcap-js/attachments:263-version-222-server-crashes-with-oom-during-file-upload-and-virus-scanningCopy head branch name to clipboard