Support creating ext alt text

[takke]

Refreshed version of PR #237 using post method from PR #260

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see https://blog.twitter.com/2016/alt-text-support-for-twitter-cards-and-the-rest-api

we can set the alt text of the attached image as below:

final UploadedMedia m = twitter.uploadMedia(file);
twitter.createMediaMetadata(m.getMediaId(), "alt metadata text");

final StatusUpdate update = new StatusUpdate(statusText);
final long[] mediaIds = new long[1];
mediaIds[0] = m.getMediaId();
update.setMediaIds(mediaIds);
twitter.updateStatus(update);

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and also added uploadMultipleImages.cmd and uploadMultipleImages.sh, it missed when I added UploadMultipleImages.java

[AndreaFalcon]

Any hope to have this merged any time soon?

[SamiSousa]

Any hope to have this merged any time soon?

@yusuke ^^^