Implement ID based iterator.
Remove 'page' parameter from some endpoints.

Using max_id/since_id or cursor is the preferred
way and sometimes the only way to paginate though a collection.
Add tests for ResultSet.
Remove some logging.
Merge ID based cursors branch.
Fix a few bugs with the new ID cursors.

 - stop once end of collection reached (empty result).
 - don't raise ValueError if ResultSet is empty when
   trying to get max/min ID of the set (max() and min() don't
   accept empty lists)
Move cursors tests into its own module.
Pass max_id and since_id into ResultSet constructor.
Merge remote-tracking branch 'master' into search-v1.1

Conflicts:
	tweepy/models.py
Fix a bug with setting max_id / since_id on a ResultSet.