Go 1.4 to include new code generation tool

wrong place to comment, no doubt, but I'd really like it if the syntax for generator instructions was separate from the comments syntax. e.g. generator instructions used another "special character" set instead of // (!!, , etc)

Two reasons:

1. How do you comment out a generator instruction?

2. A generator instruction isn't a comment, and isn't intended to be human-readable, and shouldn't be able to be confused with that.

I find the json field tagging in structs annoying for the same reason; it feels like a kludge wedged in later to make up for a gap in the original syntax.