Merge pull request #21 from PeterChu2/logo_change

Added logo for app
Change list item color on click
Added Twitter integration to sync user contacts and moved Fragments to its
own class
AsyncTask change - will fetch contacts of authenticated user
finished task to sync twitter list
Set username in sharedpreferences
Added progress updates when rate limit is reached
refresh current list after it finishes updating
Added countdown and dismissable progress dialog. Implemented wait and notify for waiting for the time until reset
Handle status so contacts are updated on return from logging in
Extract all constants to separate class
Remove private keys from github