Added Sentiment Analysis Graph Property Worker & Width, Height, FileSize Properties For Images/Videos

(Sentiment Analysis is from Stanford's CoreNLP library)
Changed pom files & lumify.properties file.

Please add:
ontology.iri.sentiment=http://lumify.io/dev#sentiment
ontology.iri.width=http://lumify.io/dev#width
ontology.iri.height=http://lumify.io/dev#height
ontology.iri.fileSize=http://lumify.io/dev#fileSize
to your lumify.properties file.

The sentiment value is represented with a number between -1 and 1, with -1 being very negative, 1 being very positive, and 0 being neutral. Sentiment analysis works on any extracted text. 

Example 1:
![sentiment analysis 2](https://cloud.githubusercontent.com/assets/7842395/3882617/c604d948-2198-11e4-86ce-08577f46d919.png)

Example 2:
![sentiment analysis](https://cloud.githubusercontent.com/assets/7842395/3882594/8c75b094-2198-11e4-83f6-8c358022b388.png)


Outstanding Issue:
When uploading a video file, two fileSize properties will be added. One fileSize is added from AudioVideoInfoWorker (correct fileSize), and the other fileSize is added from ImageMetadataGraphPropertyWorker (incorrect fileSize).