Change Compile to skip trying to load a previously compiled class

[lukaseder]

When compiling a new class, the current behaviour of first checking whether the previously loaded class already exists and loading that again is probably not what people expect, see the example here: #72

In addition to that, it's not easy to guarantee this contract across several JDK versions. It was somewhat possible in JDK 8, but not in JDK 9+.

We'll introduce this breaking change and re-compile all classes every time

[lukaseder]

Hmm, this is only asking for LinkageError trouble or otherwise significant backwards incompatible changes. We'll skip this