This replaces all use of std::optional's `opt.value()` with `*opt`
because macOS is great and the ghost of Steve Jobs says that actually
supporting std::optional's value() method is not for chumps before macOS
10.14. So don't use it because Apple is great.
Pretty much all of our use of it actually is done better with operator*
anyway (since operator* doesn't do a check that the optional has a
value).
Also replaced *most* of the `has_value()` calls with direct bool
context, except for one in the config section which looked really
confusing at a glance without a has_value().
This commit reflects changes to clang-format rules. Unfortunately,
these rule changes create a massive change to the codebase, which
causes an apparent rewrite of git history.
Git blame's --ignore-rev flag can be used to ignore this commit when
attempting to `git blame` some code.
So far only a bit of the code using timers has been modified to use
the new libuv-based timers. Also only the non-Windows case has been
implemented. Seems to be working though, so it's a good time to commit.
