pkg/tarsum: avoid buf2 allocation in Read

Docker-DCO-1.1-Signed-off-by: Cristian Staretu <cristian.staretu@gmail.com> (github: unclejack)
update the cli / man page docs based on what is in master right now

Docker-DCO-1.1-Signed-off-by: SvenDowideit <SvenDowideit@home.org.au> (github: SvenDowideit)
Remove internet dependency from TestBuildCacheADD

Signed-off-by: Alexandr Morozov <lk4d4math@gmail.com>
Add GoDoc and Travis build link/images to README

Signed-off-by: Vojtech Vitek (V-Teq) <vvitek@redhat.com>
Fix search test for busybox image

Signed-off-by: Michael Crosby <michael@docker.com>
Merge pull request #7628 from crosbymichael/fix-search-test

Fix search test for busybox image
Merge pull request #7604 from SvenDowideit/docs-update

update the cli / man page docs based on what is in master right now
Merge pull request #7613 from VojtechVitek/godoc_travis

Add GoDoc and Travis build link/images to README
Merge pull request #7602 from unclejack/tarsum_garbage_reduction

pkg/tarsum: avoid buf2 allocation in Read
Merge pull request #7608 from LK4D4/remove_internet_dep

Remove internet dependency from TestBuildCacheADD
Fix: correct cli volumes-from feature description

Options with [] may be specified multiple times. it does mean docker can
support comma separated list.
Example:
case 1, works:
docker run -it --rm --volumes-from TEST_DATA --volumes-from TEST_DATA2 ubuntu
bash

case 2, failed:
docker run -it --rm --volumes-from TEST_DATA,TEST_DATA2 ubuntu bash
2014/08/20 15:40:35 Error response from daemon: Cannot start container
e2f63ce5611c7a1be28389580d4a3847713078e6d5b61aac6cd532ec68b02191: Container
TEST_DATA,TEST_DATA2 not found. Impossible to mount its volumes

Signed-off-by: Deshi Xiao <dxiao@redhat.com>