Added a lot of basic instructions on various topics
Redundant message in basics.
Make writeBroadcaster safe for concurrent use.
Swapped a map for a list in writeBroadcaster.
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.
Merge remote-tracking branch 'dotcloud/master' into dhrp/docs
Fixed a lot of language and small things.
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
Implementing dirty git checkout indicator
Add a TestRunExit, make sure cmdRun returns after process dies
Use an environment variable to activate debug mode, instead of a package-specific flag
[unit tests] Cleanly kill all containers before nuking a temporary runtime