R=adg, r, PeterGo
CC=golang-dev
https://golang.org/cl/1942044

Depends on CL 957045, 980043, 1004043.
Fixes #715.

R=agl1, agl
CC=golang-dev
https://golang.org/cl/943043

the bash scripts and makefiles for building go didn't take into account
the fact $GOROOT / $GOBIN could both be directories containing whitespaces,
and was not possible to build it in such a situation.

this commit adjusts the various makefiles/scripts to make it aware of that
possibility, and now it builds successfully when using a path with whitespaces
as well.

Fixes #115.

R=rsc, dsymonds1
https://golang.org/cl/157067

R=rsc, agl
CC=golang-dev
https://golang.org/cl/157076

R=rsc
CC=go-dev
http://go/go-review/1019002