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>
Duplicating this at each layer doesnt make any sense, and is another
invariant where things could go wrong.
Signed-off-by: Tom DNetto <tom@tailscale.com>
This will be needed to support preauth-keys with network lock in the future,
so getting the core mechanics out of the way now.
Signed-off-by: Tom DNetto <tom@tailscale.com>
