changes to make 2 distance ranges and bug fixes

General:
- Twitter and Facebook data merged into 1 distance range
- CueSense data is now at far range

BTManager:
- compression and decompression of data
- UserConnectThread and UserConnectedThread failures communicated to
MainActivity
- UserAcceptThread recreates on restarting user threads

CompressionUtils:
- utility class to zip unzip data

CueItem:
- now sends type value in JSONObject

InfoPool:
- random items returned from all lists

MainActivity:
- discovery interval time reduced to 5 seconds
- user thread error message handling
- data sent regardless of whether it was changed or not

TextScrollFragment:
- header text changed

TwitterListFragment:
- don't add favourite tweets to the InfoPool but just display them

TwitterUtils:
- login check in getCommonFollowingsTweets()