Make writeBroadcaster safe for concurrent use.
Swapped a map for a list in writeBroadcaster.
Check if the containers are really running when starting docker
Working in progress: add unit tests for the running state check
Expand the contributing guidelines
Adding git commit to the version output

The Makefile must be used in order to inject the git commit
via -ldflags.
Shortening the git commit used in the version command
make complex options to stand out
add host name parameter to "run" command

fixes #243
add support for xz compression

This adds xz as a compression option.
xz is alread supported by bsdtar without the external xz program.
use xz compression when pushing images to the registry

This makes the xz compression the default.
fix code block formatting
Merge pull request #312 from sa2ajj/devenv-doc-fix

fix code block formatting
Merge pull request #288 from titanous/expand-contributing

Expand the contributing guidelines
Refactored CmdRun and CmdAttach to use Container.Attach
Renamed writeBroadcaster.Close() to CloseWriters().
Fix for #307
Merge pull request #317 from dotcloud/307-loginfix

Fix for #307
Merge branch 'master' into 257-container_real_running_state-fix
More thorough test case, use container.Stop() instead of lxc-kill,
use setStopped() during the restore step