improve standalone test

[MCWertGaming]

As my project broke (again) because the master master branch of cpp-terminal has functions which are not declared as static and included into two source files that get compiled together, I would like to add another source file to the stand-alone test to avoid such mistakes in the future.

[certik]

We should also probably move all functions into cpp and use the header file for declarations only. That should take care of this problem.

[MCWertGaming]

Yeah exactly. I would like to do that and then add the optional compile options I have already collected and combine them with turning all warnings into errors (which will require some extra work as the integration tests throw some warnings already).

But I think that we should merge my open pull-requests before that as they can't be merged easily after such a huge change.

[certik]

Sure. I reviewed all of them now. Let me know if anything is not reviewed.

[MCWertGaming]

Fixed in #132. Closing this...