Build script

This adds a cmake build script.

You run run it with this:

```
cmake .
make
```

It currently fails due to a lot of different warnings however i think we should merge this and then put the team on fixing the warnings.

Also i've used cmake instead of qmake that we talked about a bit before because i know cmake but not qmake so it was faster for me to solve it with cmake. See the discussion in #5 for more info about my reasons.