DirAuthority IPv6
When I try set DirAuthority to IPv6 like that:
```
DirAuthority xxxxx orport=5000 no-v2 v3ident=xxxxxxxxxxxxxxxxxxx [xxx:xxxx:xxxx:xxxx:xxxx:xxxxx:xxxx:xxxx]:7000 fingerxxxxxxxxxxxxxxxxxxxxxxxxxxxx
```
I see error in stdout:
Oct 12 16:04:44.091 [warn] Unrecognized flag
```
Oct 12 16:04:44.091 [warn] Unrecognized flag '[xxx:xxxx:xxxx:xxxx:xxxx:xxxxx:xxxx:xxxx]:7000' on DirAuthority line
Oct 12 16:04:44.091 [warn] Unrecognized flag 'fingerxxxxxxxxxxxxxxxxxxxxxxxxx' on DirAuthority line
```
**Trac**:
**Username**: svirus
issue