Use test-cases for the preprocessor

[Krzmbrzl]

I have created an entire repository of test-case input and what should be the preprocessed output of those tests here: https://github.com/Krzmbrzl/ArmaPreprocessorTestCases

In order to provide the best preprocessor result (in functionality and stability) I think it would be good practice to implement test-cases that might (or might not) be based upon my repo.
Either way test-cases should be added.

[KoffeinFlummi]

The infrastructure for those tests is there. If you want to expand on those, I'd welcome a PR.