Replaces custom logging system with spdlog-based oxen logging. This
commit mainly replaces the backend logging with the spdlog-based system,
but doesn't (yet) convert all the existing LogWarn, etc. to use the new
format-based logging.
New logging statements will look like:
llarp::log::warning(cat, "blah: {}", val);
where `cat` should be set up in each .cpp or cluster of .cpp files, as
described in the oxen-logging README.
As part of spdlog we get fmt, which gives us nice format strings, where
are applied generously in this commit.
Making types printable now requires two steps:
- add a ToString() method
- add this specialization:
template <>
constexpr inline bool llarp::IsToStringFormattable<llarp::Whatever> = true;
This will then allow the type to be printed as a "{}" value in a
fmt::format string. This is applied to all our printable types here,
and all of the `operator<<` are removed.
This commit also:
- replaces various uses of `operator<<` to ToString()
- replaces various uses of std::stringstream with either fmt::format or
plain std::string
- Rename some to_string and toString() methods to ToString() for
consistency (and to work with fmt)
- Replace `stringify(...)` and `make_exception` usage with fmt::format
(and remove stringify/make_exception from util/str.hpp).
Wires up systemd support to configure DNS on startup and when
enabling/disabling exit mode.
On startup (and when turning off an exit) we tell systemd-resolved to
direct .loki and .snode lookups to lokinet (leaving other DNS traffic
alone).
On exit enabling, we reconfigure it to resolve "." (i.e. the root DNS
domain) so that all lookups come into it.
