Rename hiercopy entry to copyfrom.

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

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.

add servicedir entry at live addon. Add enabled at configuration group entry. Move status entry from path to live addon

simplify interface of service_is_g and its functionality, provide service_get_treename as replacement

This commit sign the end of the "[WIP] allow to switch between trees" works.
The tree directory was used with s6-rc. Tree are now completely handled by
resolve file. That's means that services are not independent of a tree.
Again earn of flexibility.