Removed ErrorT and some compile errors

I removed the ErrorT instances from the code since the Get monad is able to fail itself. As a result the code behaves in an identical way but does not have deprecation warnings.
I also changed a couple of things to make sure that everything compiles error and warning free (tested on 7.8.3 and HEAD).
Lastly, I added an extra test file which is purposely cut off. This file will help to test the future incremental parser.
Apologies for a convoluted commit history, I messed it up and did not mange to clean it up.