Improve the containers unit tests (add error checking)
Added a timeout to TestCmdStreamLargeStderr.
Merge remote-tracking branch 'origin/improve_container_tests'
Merge remote-tracking branch 'robryk/cmdstream-deadlock'
Merge pull request #269 from cespare/gofmt-1

Gofmt.
Use a bytes.Reader where a strings.Reader will do.

There are a couple of places where a []byte is converted to a string
and then fed into strings.NewReader().
Don't convert []byte to string unnecessarily.
Don't use a Printf where a Print will do.
A few spelling/grammar corrections.
Don't use an interface{} where a string will do.
Fall back the gramar correction in order to match the registry server