Improve Performance

[Fleshgrinder]

The current implementation is nicely DRY, but it is not the fastest possible implementation. We always create an auxiliary array for Chars that should be ignored, at the same time this feature is seldomly used, and we are thus only producing garbage. The big when switching over the ranges is also terribly inefficient, compared to a possible jump table. These functions might be used in hot paths of applications, and should thus be fast.

This is a small isolated project to allow exactly such optimizations, because the possible code duplication that may be introduced by possible optimizations can easily be kept maintainable.