Make 'comment found' entries log at INFO level

For issue #363, this pull request makes 'comment found' items log at INFO level instead of WARN.

After this pull request is merged, the lines mentioned in that issue will look like the following (at `--verbose 4`):

```
...
INFO | BBProvisioningProfile: Comment found in BBProvisioningProfile.h@3 and BBProvisioningProfile.m@3
WARN | @propertyBBProvisioningProfile.filesystemPath is not documented!
...
```

At `--verbose 3`, the INFO line doesn't appear :)