starts the tree process after the dependencies are ready. Need to implement a communication between processes to wait for real state of a dependency

add resolve_modify_field and resolve_modify_field_g function. Rename SERVICE_STRUCT and TREE_STRUCT to DATA_SERVICE and DATA_TREE respectively

rename field deps to depends and ndeps to ndepends, add requiredby and nrequiredby field. Change interface of service_resolve_sort_bytype. Add service_resolve_create_master function

add tree_resolve_create_master, tree_resolve_modify_field, tree_resolve_field_tosa, tree_iscurrent, tree_isinitialized, tree_isenabled and tree_ongroups function