llarp/context.cpp, llarp/nodedb.{h,c}pp: load netdb AFTER whitelist
llarp/router/router.cpp: explore always
llarp/router/{i,}rc_lookup_handler.{h,c}pp explore with whitelist, update routers with lookup before stale
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.
This rewrites the version info using lokid's approach of compiling it
into a .cpp file that gets generated as part of the build (*not* during
the configure stage).
Among other things, this means that changing the version no longer
invalidates ccache or cmake dependencies, and because it depends on
`.git/index` git commits will cause the version to be regenerated,
making the commit tag more reliable (currently if you rebuild without
running cmake your git commit tag doesn't update).
This commit refactors functionality from the Router class into separate,
dedicated classes.
There are a few behavior changes that came as a result of discussion on
what the correct behavior should be.
In addition, many things Router was previously doing can now be provided
callback functions to alert the calling point when the asynchronous
action completes, successfully or otherwise.