Show AuthView only in first load of AccountView since app launch
Add newest_timeline_tweet_id_str attribute to Account entity.
Add method to sync timeline and following for each account.
Fix logic error when getting following and timeline.

Additional:
1. set threshold for recursive loading friends list and timeline to less than 198 in case API didn't return 200 items
Move get following list and timeline function to Account View.
Save newest_timeline_tweet_id_str upon successful sync.