bump Go to 1.4

Signed-off-by: Cristian Staretu <cristian.staretu@gmail.com>
Reinstall standard library with netgo

Fixes #9449

Signed-off-by: Alexander Morozov <lk4d4@docker.com>
Fix TestBuildWithTabs for go 1.4

Signed-off-by: Alexander Morozov <lk4d4@docker.com>
Merge pull request #9615 from unclejack/bump_go_to_1.4

bump Go to 1.4
Remove unused function from vfs storage driver

Signed-off-by: Pierre Wacrenier <pierre.wacrenier@gmail.com>