Evernote SDK for Mac: Async requests and file attachment support

Current HEAD of Evernote SDK for Mac OS X does not support async requests but the iOS SDK does.

So I ported modern Objective-C code (means non-thrift) from the iOS SDK.

ngs/evernote-sdk-mac

This version enables note creation very easy.

The below is an example to create new note from a PDF file as an attachment.

I have already sent a pull-request to the Evernote team. I you like this, please add comment with +1 to the pull.