fix ceph documentation issue which breaks pod2markdown.

Apparently pod2markdown is quite sensitive.

podchecker brings more readable output to find the error.

```
[wdpypere@scyther src]$ podchecker main/perl/ceph.pod
*** ERROR: Apparent command =over not preceded by blank line at line 58 in file main/perl/ceph.pod
*** ERROR: =item without previous =over at line 60 in file main/perl/ceph.pod
*** ERROR: Apparent command =over not preceded by blank line at line 88 in file main/perl/ceph.pod
*** ERROR: =item without previous =over at line 90 in file main/perl/ceph.pod
main/perl/ceph.pod has 4 pod syntax errors.
```
The first and third are the actual errors.

Should fix #256