add the ability to set some metadata to a request

[jayztemplier]

I followed those instruction to be able to add some metadata in a put request:
http://docs.aws.amazon.com/AmazonS3/latest/API/RESTObjectPUT.html

Example:

    [client putObjectWithData:imageData key:key mimeType:@"image/jpg" metadata:@{@"body" : @"custom body"} progress:^(NSUInteger bytesWritten, long long totalBytesWritten, long long totalBytesExpectedToWrite) {

    } success:^(AFHTTPRequestOperation *operation, id responseObject) {
        NSLog(@"Upload Successful! %@", [operation responseString]);
    } failure:^(AFHTTPRequestOperation *operation, NSError *error) {
        NSLog(@"Upload Failed... %@", error);
    }];

[jayztemplier]

#3

[p-l]

Won't setDefaultHeader: set that data for this and all following requests? It's fine to use it for values that will be overwritten every time like x-amz-security-token but I'm not sure it's the right thing to do for user defined metadata.

I would suggest adding them to the NSMutableURLRequest. What do you think?

[jayztemplier]

I agree, it needs more refactoring first then since we need to include those header params when we construct the string to sign. Working on it.

[jayztemplier]

It's a little bit more code but it works and set the metadata in the request headers instead of the default headers. Thanks for the feedback :)