Tree rules, current directories are removed. This is known by the master resolve file of a tree.

Tree name directories are removed. Services are not dependent anymore of a tree.
Tree name directories are replaced by a unique services directory containing all services of the system with it resolve file.

Tree resolve file handle now the list of the service name to start with a tree.

This change give the services switch between trees easily without IO access by the simplication
of the research, access of the resolve file and script of a service.

remove use of s6-rc. Split sanitize_system to new function. Revamp clone feature. Do not handle anymore backup directory at clone time. Pass to new graph_matrix_get_edge_g_sorted_sa() and graph_matrix_get_edge_g_sa() functions interface

complete revamp of the 66-tree tool: interface change, add depends/requiredby and groups features. Allow to create a tree by a seed file

[WIP] Implementation of new graph API. Implements seed file features. Use new interface of sastr_dir_get.