Use termios via CGO

Signed-off-by: Yohei Ueda <yohei@jp.ibm.com>
Merge branch 'use-termios-via-cgo' of github.com:yoheiueda/docker into use-termios-via-cgo
Revert "Use termios via CGO"

This reverts commit d521825d2915e619339a4cf6595e4d8275d28317.
Use termios via CGO on Linux

Signed-off-by: Yohei Ueda <yohei@jp.ibm.com>