use this horrible complex bit of shell to make sure that curl doesn't hand the poor user a broken docker client

Docker-DCO-1.1-Signed-off-by: Sven Dowideit <SvenDowideit@fosiki.com> (github: SvenDowideit)
mention the tgz - other people might like to know

Docker-DCO-1.1-Signed-off-by: Sven Dowideit <SvenDowideit@fosiki.com> (github: SvenDowideit)
OSX mktemp is different - hopfully this will now work on HP/UX >:}

Docker-DCO-1.1-Signed-off-by: Sven Dowideit <SvenDowideit@fosiki.com> (github: SvenDowideit)
Remove runtime options from config
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)
Remove driver wide mount label for dm
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)
Remove archive/stat_unsupported.go because it is not used

LUtimesNano and all other functions were implemented on pkg/system after
d6114c0da0e844199e3d23c60a04434566fb5392.

Docker-DCO-1.1-Signed-off-by: Kato Kazuyoshi <kato.kazuyoshi@gmail.com> (github: kzys)
Don't assume the file system has sub-second precision timestamp

For example, FreeBSD doesn't have that
(see http://lists.freebsd.org/pipermail/freebsd-fs/2012-February/013677.html).

Docker-DCO-1.1-Signed-off-by: Kato Kazuyoshi <kato.kazuyoshi@gmail.com> (github: kzys)
intermediate image layers are used for more than the build

Docker-DCO-1.1-Signed-off-by: Sven Dowideit <SvenDowideit@fosiki.com> (github: SvenDowideit)
Merge pull request #5051 from SvenDowideit/build-rm-help

intermediate image layers are used for more than the build
Merge pull request #5038 from kzys/remove-archive-stat

Remove archive/stat_unsupported.go because it is not used
Merge pull request #5039 from kzys/freebsd-timestamp

Don't assume the file system has sub-second precision timestamp
Merge pull request #5040 from crosbymichael/remove-context-from-config

Remove context from config
Merge pull request #4764 from SvenDowideit/use-docker-tgz

Use docker tgz file to download on OSX