added in/outdev getters and performance improvements.

[DOWRIGHTTV]

here is an example of what i am talking about. it is a derivative work of this repo from last year that actually takes on the basic protocol parsing for the user and releases the GIL prior to parsing. https://github.com/DOWRIGHTTV/dnx_nfqueue/blob/master/dnx_nfqueue.pyx

[oremanj]

I recently added indev/outdev attributes using a different approach. Closing this since you didn't respond to my comments.