add support for COPY to docker build

This adds a COPY command to docker build which works like ADD, but is
only for local files and it doesn't extract files.

Docker-DCO-1.1-Signed-off-by: Cristian Staretu <cristian.staretu@gmail.com> (github: unclejack)
sync the initial docs from b2d

Docker-DCO-1.1-Signed-off-by: SvenDowideit <SvenDowideit@home.org.au> (github: SvenDowideit)
Refactor device handling code

We now have one place that keeps track of (most) devices that are allowed and created within the container.  That place is pkg/libcontainer/devices/devices.go

This fixes several inconsistencies between which devices were created in the lxc backend and the native backend.  It also fixes inconsistencies between wich devices were created and which were allowed.  For example, /dev/full was being created but it was not allowed within the cgroup.  It also declares the file modes and permissions of the default devices, rather than copying them from the host.  This is in line with docker's philosphy of not being host dependent.

Docker-DCO-1.1-Signed-off-by: Timothy Hobbs <timothyhobbs@seznam.cz> (github: https://github.com/timthelion)
reuse timestamp, don't call time.Now() 3 times

Docker-DCO-1.1-Signed-off-by: Cristian Staretu <cristian.staretu@gmail.com> (github: unclejack)
Merge pull request #6127 from unclejack/reuse_timestamp

reuse timestamp, don't call time.Now() 3 times
Merge pull request #6097 from timthelion/consistentdevices

Refactor device handling code
Init database if empty file
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)
Ensure all dev nodes are copied for privileged

This also makes sure that devices are pointers to avoid copies
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)
Merge pull request #6129 from crosbymichael/copy-all-in-priv

Ensure all dev nodes are copied for privileged
Merge pull request #6128 from crosbymichael/empty-sqlite

Init database if empty file
Updated link to new docker-node-hello repository
Merge pull request #6073 from SvenDowideit/b2d-port-redirection-docs

sync the initial port redirection docs from b2d
Merge pull request #6089 from unclejack/docker_build_copy

add support for COPY to docker build
Add documentation build steps for the next release manager to follow.

Docker-DCO-1.1-Signed-off-by: SvenDowideit <SvenDowideit@home.org.au> (github: SvenDowideit)
Merge pull request #5924 from SvenDowideit/docs-build-instructions

Add documentation build steps for the next release manager to follow.
Merge pull request #6140 from zanedeg/patch-1

Updated link to new docker-node-hello repository