For now, the tree is always considered at up/down. The ssexec_{start,stop} deal with the state of the service anyway

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 option come from previous behavior. It not the role of enable process
to deal with parse option.
Also, this change allow user to quickly switch between trees without the need
to force a parse process.
The necessary field at resolve file of the service is now handled by enable
process.