Modify

1. SentimentValue.java
- Total will not equal to 1 after SentiWordNet calculation.
- Change value with restriction after operation add and div.
- add tostring()
- add equales()

2. SentimentDictionary.java
- Modify value calculation to class SentimentValue.
- return will be SentimentValue object

Add
1. SentimentDictionaryTest.java
- basic sentiment value with SentimentWordNet format input
- basic sentiment value with OpenNLP format input