Unindent winchan inside include.js

Given that this will be minified later, there's not much value in
changing the indentation and it makes diffing with the real
winchan much more difficult.
Remove comments from winchan embedded in include.js

This is a follow-up to aa692aee0fd2257dfe6b7a1492c558b2aa6ca780 to
make this file identical to the upstream version of winchan and
more easily detect discrepancies.
Update local copies of winchan with latest upsteam version

This is commit ebc34779cd4d9d91867ad7b71bb8c274a3285e36 from the
mozilla/winchan repo.
Merge pull request #3758 from fmarier/update_winchan

Update winchan