Added main interfaces and value objects
Added Query and QueryTweetStream
More docs and methods added to HashtagCounter
Added first TweetStream implementation and a simple TweetListener (TweetEchoer)
Major reorganization. Now using Maven. Added some test code.
added tests for TweetHistory
Added TopicTweetStream
Completed the BasicTopicTweetStream and added TopicDefinitionChangeListener
added a cast to double

Without the cast the intersection is an int division and the result is always zero...
Added graphical DTS
Added graphical DTS