Can't name project `Whathecode.System`.

Due to a [possible bug in Visual Studio 2017 RC](https://developercommunity.visualstudio.com/content/problem/6687/problems-loading-project-reference-in-the-case-of.html), the project can currently not be named `Whathecode.System` since that breaks compilation, as well as IntelliSense.

Therefore, for now (until this bug is fixed) the project is named `Whathecode.System (Core)`.