This updates all source files to use a new standard header for copyright
and license declaration. Notably, copyright no longer includes a date,
and we now use the standard SPDX-License-Identifier header.
This commit was done almost entirely mechanically with perl, and then
some minimal manual fixes.
Updates #6865
Signed-off-by: Will Norris <will@tailscale.com>
Add a mode control for derp server, and add a "manual" mode
to get derp server certificate. Under manual mode, certificate
is searched in the directory given by "--cert-dir". Certificate
should in PEM format, and use "hostname.{key,crt}" as filename.
If no hostname is used, search by the hostname given for listen.
Fixes#2794
Signed-off-by: SilverBut <SilverBut@users.noreply.github.com>