add options menu item for log out flows

add logout menu item for facebook, twitter and linkedin fragments
enhance list performance of facebook friend list

replace the ProfilePictureView of facebook sdk by ImageLoader of
custom-ui of SocialAuth. update the database support of storing the
profile image url of facebook
Merge pull request #16 from mrstrlc-yipeng/yipeng-v2

add options menu item for log out flows
enhance list performance of facebook friend list