Default log file removed and other cosmetic fixes

logrotate file has been removed because:
- /usr/libexec/storm-info-provider configure ... prints log messages on
stdout
- /usr/libexec/storm-info-provider
{get-serving-state,get-static-ldif,get-update-ldif}
... prints log messages on stderr
- BDII's /var/log/bdii/bdii-update.log contains the stderr from the
script located into /var/lib/bdii/gip/plugin

So, by default, a log file isn't really necessary.
However, we decided to keep the possibility to specify a log file with
the -o command line option.