Improve error for docker exec & LXC

Signed-off-by: Victor Vieux <vieux@docker.com>
Fix code example formatting in best-practices article

Signed-off-by: Lajos Papp <lajos.papp@sequenceiq.com>
Fix quoting of TESTFLAGS in devenvironment.md

Copy and pasting the example should now work, rather than TESTFLAGS being silently ignored.
Merge pull request #8212 from hugoduncan/patch-1

Fix quoting of TESTFLAGS in devenvironment.md
Merge pull request #8205 from sequenceiq/master

Fix code example formatting in best-practices article
Updated output from the docker cli help

Docker-DCO-1.1-Signed-off-by: SvenDowideit <SvenDowideit@home.org.au> (github: SvenDowideit)
Provide full hostname with domainname to underlying container layer
Addresses #7851

Docker-DCO-1.1-Signed-off-by: Phil Estes <estesp@linux.vnet.ibm.com> (github: estesp)
Add checks for app/json - issue #2515

Signed-off-by: Doug Davis <dug@us.ibm.com>
builder: Fix handling of VOLUME command where multiple volumes are
specified in a space delimited list.

Docker-DCO-1.1-Signed-off-by: Erik Hollensbe <github@hollensbe.org> (github: erikh)
Merge pull request #7994 from erikh/parser_fix_volume_parsing

builder: Fix handling of VOLUME command where multiple volumes are specified in a space delimited list.
Merge pull request #8208 from estesp/7851-fix-hostname-fqdn

Provide full hostname with domainname to underlying container layer
Pull all image aliases for id. Closes #8141.

Docker-DCO-1.1-Signed-off-by: Jessica Frazelle <jess@docker.com> (github: jfrazelle)
Merge pull request #8235 from duglin/Issue2515

Add checks for app/json - issue #2515
Merge pull request #8228 from SvenDowideit/latest-commandline-doc-changes

Updated output from the docker cli help
Merge pull request #8193 from jfrazelle/8141-pull-all-image-aliases-for-id

Pull all image aliases for id
devmapper: include the version in `info`

Signed-off-by: Vincent Batts <vbatts@redhat.com>
not not -> not

Signed-off-by: Victor Vieux <vieux@docker.com>
hack: TIMEOUT (for controlling test timeout) and forwarding of
BUILDFLAGS to binary/dynbinary.

Docker-DCO-1.1-Signed-off-by: Erik Hollensbe <github@hollensbe.org> (github: erikh)
Merge pull request #8243 from vieux/not_not

not not -> not
Merge pull request #8239 from erikh/hack_options

hack: TIMEOUT (for controlling test timeout) and forwarding of BUILDFLAGS to binary/dynbinary.