* remove endpoint discovery noise when results unchanged
* consistently spell derp nodes as "derp-N"
* replace "127.3.3.40:" with "derp-" in CreateEndpoint log output
* stop early DERP setup before SetPrivateKey is called;
it just generates log nosie
* fix stringification of peer ShortStrings (it had an old %x on it,
rendering it garbage)
* describe why derp routes are changing, with one of:
shared home, their home, our home, alt
staticcheck defaults to running with no tags set, which only
works if redo hasn't run and generated ver.go. If it has,
we end up with a redeclaration conflict.
Signed-off-by: David Anderson <dave@natulte.net>