At write time:
  - Add the whole sa to the new cdb field named sa instead of storing the key one by one.
  - Store uniquely the uint of the key instead of appending a string.

At read time:
  - Do not build again the sa looking for the cdb value but read the whole sa instead.
  - Do not use extra HEAP memory allocation.
At modification time:
  - Sanitize the resolve by writting the sa from scratch.
  - Use /tmp directory as temporary cdb file.
Replace resolve_find_cdb by the resolve_get_key and resolve_get_sa function.
Replace service_resolve_copy by service_resolve_sanitize.

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.

add service_resolve_write_tmp and state_write_tmp function to be able to write those files at a temporary directory

Thanks for your service! This resolve file was used with s6-rc. The things now are simplier
and flexible.

service Master resolve file is no longer a service incorporate to the DB. It was reorganize to provide mandatory field to be a real Master. This file will now be used to known the global state of the services.