* Use fork instead of spawn
We no longer do in-place updating so no need for the spawn. The
advantage of a fork is that it preserves flags like --prof which you can
use to profile code-server.
Also I am not sure the comment about not being able to reload in place
with fork was even true to begin with.
* Refresh heartbeat patch
Seems to have gotten out of date a little.
* Propagate execArgv to extension host
This will let us profile the extension host.