From pull request #549. Changes include:
* Use OptEnum to enforce the use of wpad.dat or proxy.pac
* Remove cli.peerhost:cli.peerport, the API does that already
* cleanup function to restore uripath datastore option
* More friendly error when the user doesn't have enough permission
to bind to port 80, that way they don't blame it's a bug on msf.
* Remove unnecessary SVN stuff in modinfo