Completed functionality of adding and removing likes and dislikes. 

I have yet to complete the functionality of seeing that an abstract has already been liked or disliked. I am still working on that. 

Now if an abstract that has already been liked is disliked, it will be removed from liked and placed into disliked. 

I apologize for the exorbitant amount of code in there. I still think it's fairly readable and I'm not sure how to trim it down. 

Sorry for misleading branch name.