added weka classification
added weka classification - merged
Merge origin/master

Conflicts:
	src/at/tuwien/aic/Main.java
	src/at/tuwien/aic/preprocessing/PorterStemmer.java
	src/at/tuwien/aic/preprocessing/Stem.java
	src/at/tuwien/aic/preprocessing/StopWordRemoval.java
	src/at/tuwien/aic/twitter/TweetCrawler.java
	src/resources/stopwords.txt