Better errno handling

Add islog internal key to quickly is the resolve file concern the logger itself.
Add the rversion internal field. This field will be used to know the previous
version of the resolve file and possibly make an
automatic migration of the db to the new format.

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.

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.

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.

Permit to set uid and gid for a run script.
Unknown key may occur at end of the file.
Avoid to changed pointer.
Typo fix.

This is avoid having supplementary directories at
SS_SERVICE_ADMDIR or SS_SERVICE_USERDIR mostly in case of crash of
module parse process. In that case, as the resolve file of the module is not
created yet, it cannot be found at remove time.

This reverts commit 87bd69c6.

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