New configuration parameter exempt_pod

Hello,

I have implemented a configurable parameter exempt_pod for allowing the user of the policy to specify that POD should not be evaluated. This is a first shot, I would love to be able to do this on two levels so I could differentiate keywords matching actual part of POD and casual comments in POD, but this would require a POD parser. This first implementation can be regarded as a starting point for further exploration of the problem area.

Looking forward to hearing from you,

jonasbn