RFC822 should zip files when attachments are folders

[dinhvh]

[dinhvh]

The zip file should be saved in NSTemporaryDirectory or /tmp.
It should be a C++ implementation.

[dinhvh]

https://github.com/AgileBits/objective-zip can help.

[dinhvh]

nice API for archiver could be:
CreateZipFileFromFolder(String * zipFilename, String * folder, ErrorCode * pReturnValue);