Don't set the MTU for loopback interfaces.

Setting the MTU for loopback has a huge performance impact on intra-container
traffic. The loopback interface is not an ethernet interface and does not need
the same limit. with this change I see a 4x speedup for loopback throughput.

Docker-DCO-1.1-Signed-off-by: Tim Hockin <thockin@google.com> (github: thockin)
Merge pull request #98 from thockin/netperf

Don't set the MTU for loopback interfaces.
Remove terminal handling in libcontainer
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@docker.com> (github: crosbymichael)
Open with NOCTTY and set raw term
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@docker.com> (github: crosbymichael)
Add resize of term in tty mode
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@docker.com> (github: crosbymichael)
Don't open slave in parent
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@docker.com> (github: crosbymichael)
Merge pull request #99 from crosbymichael/improve-term-handling

Remove terminal handling in libcontainer
Add dockerfile
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@docker.com> (github: crosbymichael)
Merge pull request #100 from crosbymichael/add-dockerfile

Add dockerfile
Add linux build tags for selinux
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@docker.com> (github: crosbymichael)
Merge pull request #101 from crosbymichael/selinux-build-tags

Add linux build tags for selinux
Update a few build tags to be more generic, add a couple more SETNS constants, and update Travis with a bunch of fixes/tweaks (including removing the nonfunctional cross-compile stuff for now)

Docker-DCO-1.1-Signed-off-by: Andrew Page <admwiggin@gmail.com> (github: tianon)
Add Exec to container API
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@docker.com> (github: crosbymichael)
Merge pull request #102 from crosbymichael/add-exec

Add Start to container API
Merge pull request #104 from tianon/more-generics

Update a few build tags to be more generic, ...
Reopening stdin, stdout and stderr if they are pointing to /dev/null to not have '/dev/null' from the global namespace opened inside the container.

Docker-DCO-1.1-Signed-off-by: Vishnu Kannan <vishnuk@google.com> (github: vishh)