Updating to latest masters

Deployed new service (2b2816081120a5e65f5bf80c294b2a85a1de38f8):
* Double cache lifetime of successful renders, to 4 days.
* Send SIGKILL if SIGTERM doesn't do the job (after execution timeout).

Deployed new bundler (a93dd0c9935cb6db56da4f6289d66adbdc0710d3):
* Better debugging if article name resolution fails.

Deployed new latexer (c4c7f7515ea337f05c2d4d851029ba90e469a8f8):
* Add `--helper-exec-limit` option to protect against runaway image helpers.

Change-Id: Id4846bb6d0a6aa751a82a81074535c30e06a4e5e
Merge branch 'master' into wmf-deploy

Change-Id: I61d4b6157ea50a67548b5c7c49e09ca0b5ca3e62