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
delete strings.Buffer
add a test for a bug not caught before (mustn't install zero-length blocks)
R=rsc
DELTA=987 (289 added, 587 deleted, 111 changed)
OCL=34850
CL=34850
