fix(daemon): ensure the /var/lib/docker dir exists

The btrfs driver attempts to stat the /var/lib/docker directory to
ensure it exists. If it doesn't exist then it bails with an unhelpful
log line:

```
2014/05/10 00:51:30 no such file or directory
```

In 0.10 the directory was created but quickly digging through the logs I
can't tell what sort of re-ordering of code caused this regression.

Docker-DCO-1.1-Signed-off-by: Brandon Philips <brandon.philips@coreos.com> (github: philips)
Dockerfile: updated ubuntu release used for builds

This patch just revs the Ubuntu release used for builds from 13.10
to 14.04.

Docker-DCO-1.1-Signed-off-by: Aleksa Sarai <cyphar@cyphar.com> (github: cyphar)
Fix bug on LXC container start. Fixes #5718
Docker-DCO-1.1-Signed-off-by: Fernando Mayo <fernando@tutum.co> (github: fermayo)
libcontainer: Create dirs/files as needed for bind mounts

If you specify a bind mount in a place that doesn't have a file yet we
create that (and parent directories). This is needed because otherwise
you can't use volumes like e.g. /dev/log, as that gets covered by the
/dev tmpfs mounts.

Docker-DCO-1.1-Signed-off-by: Alexander Larsson <alexl@redhat.com> (github: alexlarsson)
Correct a comment in libcontainer Mount Namespace setup.
Docker-DCO-1.1-Signed-off-by: Vishnu Kannan <vishnuk@google.com> (github: vishh)
Merge pull request #5712 from vishh/fix_typo

Correct a libcontainer Mount Namespace setup comment.
Merge pull request #5724 from tutumcloud/5718-lxcbugfix

Fix bug on LXC container start. Fixes #5718
Remove newline char in error message
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)
Merge pull request #5748 from crosbymichael/libcontainer-bindmounts

libcontainer: Create dirs/files as needed for bind mounts
Merge pull request #5696 from cyphar/rev-ubuntu-dockerfile

Update Ubuntu release used for builds
add vieux as server's MAINTAINERS

Docker-DCO-1.1-Signed-off-by: Victor Vieux <vieux@docker.com> (github: vieux)
Merge pull request #5750 from vieux/vieux_server_maintainer

add vieux as server's MAINTAINERS
Merge pull request #5717 from philips/mkdir-in-daemon

fix(daemon): ensure the /var/lib/docker dir exists
move version out of server

Docker-DCO-1.1-Signed-off-by: Victor Vieux <vieux@docker.com> (github: vieux)
Merge pull request #5751 from vieux/move_version

move version out of server