Moves multipart tweeting to twit callback to ensure order
Fix to prevent overflow of multitweet if the twitter API reports error.
Revert "Fix to prevent overflow of multitweet if the twitter API reports error."

This reverts commit 90deb598ab3c8686873b71bca250a0df02e1740d. The math was wrong, it should work fine with only the first commit.
Merge pull request #2 from nocko/master

Moves multipart tweeting to twit callback to ensure order