Clean up and organize tests + state class tests

I removed the complete create/call functionality of the FakeExtVM leaving it to minimum functionality, creating a "callcreate" in the test. Tests needing those functions should be written as state tests (new feature).
I created a lot of helper functions in order to reuse code.

True, but it would really add quite a lot of code in the exportTest function. All I do here is make sure it is EVM code in the object and not LLL. I think it is ok to have it here although it is only needed for the export.