metrics re-arch

[matthsmi]

Butler has 5 phases

with the simplified decision flow of....
If 200 then set metrics & set LKG
If timeout then set metrics (if timeout_ok = false) & leave the files on disk (do not delete)
If !200 then set metrics and restore LKG to disk

butler_

1. connection to the remote file store, could be S3/http etc
   _remote_status{file="myfile} = return code of remote, 200 for http, not sure for s3
   _remote_time{file="myfile} = timestamp of last time we got the file

Phase 1 will happen every interval, so we can use timestamps, phases below are not guanteed to happen every interval, only if the files changes, so we cannot use timestamps for alerting....

2. config parsing
   _cfg_mustache{file="myfile} = 0 or 1
   _cfg_render{file="myfile,method="yml|json|text} = 0 or 1

3. write files to disk
   _write{file="myfile} = 0 or 1

4. reload config
   _reload_status{manager="myman"} = return code when reloading, 0 for timeout
   _reload_time{manager="myman"} = timestamp of last attempted reload (be it fail, succeed or timeout)

_lkg{manager="myman"} = timestamp of the when the last known good was stored.