add websocket support to /container/<name>/attach/ws

This function add the possibility to attach containers streams to a
websocket. When a websocket is asked the request is upgraded to this
protocol..
change tag -> repo name in build usage
put the websocket route in the map containing all routes

Instead of handling the websocket differently just handle it as a normal
route and upgrade it to a websocket.
useless type
useless function. forgot to remove it.
reuse the type
add server.ContainerTop, server.poolAdd and ser.poolRemove tests
Add CompareConfig test
prevent any kind of operation simultaneously
add Volumes and VolumesFrom to CompareConfig
add VolumesFrom to MergeConfig, and test
+ Runtime: inject dockerinit at /.dockerinit instead of overwriting /sbin/init. This makes it possible to run /sbin/init inside a container.
change permissions of initLayer to be readable by non-root users
rebase master
Add ID to JSONMessage in pull
Use goroutines to pull in parallel
If multiple images pulled at the same time, each progress is displayed on a new line
improve client output
Library: hipache and ubuntu base
Adding Joffrey as library maintainer
Define tags in the library files instead of upstream
Use extended syntax (indicate what type of object needs to be checked out)