Fix broken checks and add a couple of new ones. 

Few bug fixes. 

As a reminder these are functional checks on the system and designed to be run either interactively to help debug a system, or by zabbix/collectd/etc..

e.g.
```
root@bcpc-vm1:~# check
+-----------+-------+---------+-----+
|    name   | state |   time  | msg |
+-----------+-------+---------+-----+
|   mysql   |  OKAY |  0.102  |     |
|    nova   |  OKAY | 134.450 |     |
| float_ips |  OKAY |  0.503  |     |
|   apache  |  OKAY |  0.102  |     |
|    rgw    |  OKAY |  1.507  |     |
+-----------+-------+---------+-----+
```

There are two new checks:
apache: checks apache is listening on mgmt and float 
mysql: checks that the local mysqld is clustered correctly.