std::isspace does not work on some unicode chars, breaks IncludeProcessor

this line here https://github.com/cginternals/globjects/blob/17dcc4c5129259781bdb9251294518f2a0c75472/source/globjects/source/IncludeProcessor.cpp#L24

was failing for me in debug mode when processing a line that had this comment inside it:
```
// ¯\_(ツ)_/¯
```

this is also mentioned in the comments of the linked stackoverflow post.