filter flag: split out for separate --filter flags

adding tests and allowing for easy passing of filters.Args from client
to server.

Docker-DCO-1.1-Signed-off-by: Vincent Batts <vbatts@redhat.com> (github: vbatts)
server: very debug.

Docker-DCO-1.1-Signed-off-by: Vincent Batts <vbatts@redhat.com> (github: vbatts)
filters: change untagged to dangling

Docker-DCO-1.1-Signed-off-by: Vincent Batts <vbatts@redhat.com> (github: vbatts)
filters: use json marshal, instead of beam/data

Docker-DCO-1.1-Signed-off-by: Vincent Batts <vbatts@redhat.com> (github: vbatts)
filters: don't encode an empty set. update comments

Docker-DCO-1.1-Signed-off-by: Vincent Batts <vbatts@redhat.com> (github: vbatts)
Merge pull request #6165 from vieux/update_tests

Update tests regarding busybox & inspect
switch skipping from error to debug

Docker-DCO-1.1-Signed-off-by: Victor Vieux <vieux@docker.com> (github: vieux)
Merge pull request #6166 from vieux/debug_skipping

switch skipping from error to debug
Merge pull request #5848 from unclejack/resumable_pulls

resume pulling the layer on disconnect
add proto validation at parse

Docker-DCO-1.1-Signed-off-by: Victor Vieux <vieux@docker.com> (github: vieux)
add volumes back to inspect

Docker-DCO-1.1-Signed-off-by: Victor Vieux <vieux@docker.com> (github: vieux)
Merge pull request #6169 from vieux/add_volumes_inspect_back

add volumes back to inspect
Add redirect and env proxy support to docker login

Docker-DCO-1.1-Signed-off-by: Victor Vieux <vieux@docker.com> (github: vieux)
Merge pull request #6153 from vishh/stats1

Add per cpu usage to libcontainer  stats
Merge pull request #6168 from vieux/add_proto_validation

add proto validation at parse
Merge pull request #6056 from ipbabble/master

Made fixes to man pages to remove some ambiguities and typos
Merge pull request #6143 from LK4D4/move_some_more_tests_to_cli

Move some more tests to integration cli
Ensure that ownership and perms are copied to volume

This only works if the file or dir is already created in
the image before setting it to be a volume.  There is no way around this
because we don't have the data avaliable to set the volume at the
beginning of the dockerfile
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)
Add test for volume ownership and perms
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)
Merge pull request #6170 from vieux/redirect_login

Add redirect and env proxy support to docker login