crypto/openpgp

Hi,

I'd like to clarify crypto/openpgp.NewGpgFile's comments, and maybe add a WrapFile function, to be able to use any *os.File (or alike) object - esp. os.Stdout, in my use case.

The other changes in crypto/openpgp/actions.go are totally subjective (don't declare variables before the need, use Go's type inference).

go fmt ./... would make reading & contributing waay easier!

Thanks,
Tamás Gulácsi