This adds support for tailscaled to be an HTTP proxy server.
It shares the same backend dialing code as the SOCK5 server, but the
client protocol is HTTP (including CONNECT), rather than SOCKS.
Fixes#2289
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
We have different deps depending on the platform.
If we pick a privileged platform, we'll miss some deps.
If we use the union of all platforms, the integration test
won't compile on some platforms, because it'll import
packages that don't compile on that platform.
Give in to the madness and give each platform its own deps file.
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>