Adding Go directory and example

Here is a driver and demo in Go. (http://golang.org)

I added 'go' in the top-level directory, consistent with 'java' and 'processing' as other languages. 

Within that directory, I added the GoBlink example, which is essentially a command line demo. 

goBlink.go     This is a demo that uses the hid.go wrapper
hid.go         This is a Go wrapper around the C drivers
hiddata.c      These are slightly modified from the original C USB drivers
hiddata.h

--Gary