Commented Feature: Update : [code/unity] Migrate application design to use Unity for IoC [1691]

Implement Unity and Dependency injection to enable the development of Unit Tests as Tweetinvi currently only have Integration tests.
Comments: Associated with changeset 33401: Version 0.9.0.0
- Implemented SearchTweets with all the existing parameters
- Implemented Language enum which contains all the languages that are available in Twitter