* correct dependency calculations
* comment meaning of action fields
* new alias "std" like "all" but standard packages only
* add -o flag to 'go build'
* set up for parallel build (still serial)
* understand that import "C" depends on cgo, runtime/cgo
R=golang-dev, mikioh.mikioh
CC=golang-dev
https://golang.org/cl/5502055
If something goes wrong, it should suffice to set
USE_GO_TOOL=false in env.bash to fall back to the
makefiles. I will delete the makefiles in January.
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/5502047