init fix

1. 
We keep some old logs after snapshot. So the ```startIndex```  should be the index of the log before the first entry in the log.

2.
```Compact()``` should also compact ```log.results```

3.
```confFile``` should be cleared after loading peer information.
```AddPeer``` command will help to rewrite the confFile.

4.
Some minor debug info and checking error fix.