Adds the Twitter buttons to your nodes.
Choose which content type, and if the button should show on teasers or full nodes.
1) Tweetbutton will be a field. Can be attached to any entity
2) Each entity page can specify an author twitter account info, and a custom tweet text to be use as the text for the tweetbutton on that page.
3) The tweet text and author account can be token strings. One can create a user field "Twitter account" and add a token [node:author:field_twitter_account]. If no twitter account was specified, it will fallback to default site twitter account.