Rename hiercopy entry to copyfrom.

The dependencies was displayed at first level of identation
making confusing the comprehension of the list.
The dependencies whatever the associated tree to that dependency is displayed
at depth level above 1.

Provide new keyword stdin, stdout and stderr at -o options.
Decrease number of logger line to display to 10.

Prevent user to remove service inside a module.

Destination field is replaced by StdXXX key field.
StdXXX s6log type accept now path for a specific destination.

Remove deprecated options 'n', 'a', 'd', 'C', 'S'.

Allow to use an existing snapshot at upgrade time

the version of the system and the version of services

create, restore, remove and list are available.
These subcommand do not affect the state of a running services.

See commit 3f345ecb
Rename tree_resolve_copy and tree_resolve_master_copy to
tree_resolve_sanitize and tree_resolve_master_sanitize respectively.

Rename TimeoutKill to TimeoutStart.
Rename TimeoutFinish to TimeoutStop.
Remove TimeoutUp and TimeoutDown key.
To avoid confusion and mistake, oneshot and classic service use now
the same key name to declare the timeout to use.
TimeoutStart and TimeoutStop are clearer than TimeoutKill and TimeoutFinish.
66 is sufficiently smart to name the file correctly for s6-supervise
whick look for the timeout-kill and timeout-finish file.

The status command without options return now an overview of all services
from all trees. This is similar as 66 tree status command but with a
shorter call and less informations.

Fix redirection to get sulogin message.
Handles environment properly before managing init configuration file.

Each tool needs to be independent, which
meant that every time a tool was called,
it would build the entire system graph.
This was an obvious waste of time and resources.

Now, the tools build the graph based
on the requested services, which
drastically reduces the time needed to
construct the necessary dependency graph.

Logger destination directory for a service
inside a module was not deleted.