Added Go advent 2014 article

Hi Brian,

I took the text of your Go Advent post to golang-nuts and converted it into blog post for the GA blog.

I set the date to 27th of Nov, but ideally any time between now and then works for me. 

I need this to link to for my Go meetup group on the 27th, so actually, yes, this should be merged earlier as it'll be the day before in the US.

Cheers

Dave