This adds the X-Smokescreen-Role header to proxy connections, to track
usage from various codepaths, and enforces a timeout. Timeouts were
kept consistent with their previous values, or set to 5s if they had
none previously.
Leave the Intel build as the prominent default, since it will run on
both platforms. (I would have liked to detect the appropriate
platform, but Apple seems to have put significant effort into making
that impossible for anti-fingerprinting reasons, which is probably an
overall good.)
Signed-off-by: Anders Kaseorg <anders@zulip.com>
Alex Vandiver
Anders Kaseorg
Vishnu KS