bugfixes: typo, making QuadgramCollocationFinder readable

Signed-off-by: Ofer Helman <helmanofer@gmail.com>
added window to from_words in quadgram finder

Signed-off-by: Ofer Helman <helmanofer@gmail.com>
new QuadgramAssocMeasures Calculates quadgram contingency table

Signed-off-by: Ofer Helman <helmanofer@gmail.com>
removed un relevant file

Signed-off-by: Ofer Helman <helmanofer@gmail.com>