Large PR with many advancements: I am happy to discuss how to merge these changes

Hi @sgvandijk, thanks for your support so far, I greatly appreciate it!

I have refactored all my non-SPL context code that were in naosoccer_sim to this branch so that it could benefit a wider audience. I have tried to organize all commits in a logical order (with sensible messages), but I find it hard to raise independent PRs as there is refactoring involved in the earlier commits.

How would you like to proceed with these changes? If you are happy to go ahead and look at each commit in this PR and comment on changes, that's fine with me.

Thanks!