'expand links' link in UI doesn't work if one of the URLs is truncated with ellipsis

[kerchner]

This can sometimes occur in the case of a retweet. Clicking the "expand links" link for a tweet of this type in the /twitter-user/AccountXYZ page results in no action. Even when the tweet contains 2 or more URLs, and only one is truncated, the expand links link doesn't open.

This issue is related to #311, where the fetch_urls process is also not dealing with links that are truncated. As noted in #311 (as well as in associated PR #334) the tweet json in the case of a retweet should (usually?) contain the original, non-truncated URL(s). We should consider getting the URL from the ['retweeted_status']['urls'] node.

For an example, refer to the tweet json pasted in the comments of #334.