Support saveEventually on Files

[mithleshjs]

Now that we can host parse on our own server, add support for saveEventually on files.

[grantland]

I wouldn't recommend this. If you wanted to upload a large file I'd suggest throwing the upload into a background service in a different process.

[mithleshjs]

How about uploading files less than 500 KB ?

[grantland]

I don't have any argument against this, however, I would strongly suggest that the current *Eventually stack should be nuked and reimplemented externally of ParseObject first.

[timLoewel]

Is putting the file upload into a background task not part of the scope of the Parse-SDK?
I was surprised, when I learned, that the file-upload does not work in the background.
Without background upload parse-files are unusable for me. A mobile device nearly never has steady network access.