libgo: Bring over http/cgi environment inheritance patches.
libgo: Bring over http/cgi environment inheritance patches.

R=iant
CC=gofrontend-dev
https://golang.org/cl/4450051

anlhord/gofrontend,qskycolor/gofrontend,qskycolor/gofrontend,anlhord/gofrontend,golang/gofrontend,qskycolor/gofrontend,anlhord/gofrontend,anlhord/gofrontend,anlhord/gofrontend,golang/gofrontend,qskycolor/gofrontend,golang/gofrontend,anlhord/gofrontend,qskycolor/gofrontend,anlhord/gofrontend,golang/gofrontend,qskycolor/gofrontend,qskycolor/gofrontend