Include rename/move information if diffs served by API

The current bitbucket diff APIs do not handle move/renames in a smart manner. If I run git diff on the command line I get information as far as a file being renamed and similarity score. Bitbucket APIs return two separate diffs, an add and a delete, even if the contents are unchanged. In addition, this functionality seems to already be available for the actual bitbucket UI (eg: https://blog.bitbucket.org/2016/04/14/updated-diff-view-for-moved-or-renamed-files/), but not to the API. This makes it difficult for an integrating application to get an idea of the diff that an end-user is seeing without doing all of the diffing logic themselves.