[boost] [gil] Google analytics script tags

Hi, If you've missed it, there was a recent thread about using google analytics in offline copies of boost and the consensus was firmly against them. The gil documentation includes the google analytics javascript but doesn't seem to use it. So I assumed that their inclusion was a mistake and went ahead and removed them on trunk. I hope that wasn't presumptuous. But I did this on the generated documentation as I couldn't work out how it is generated. It'd useful to have some brief instructions and any necessary files. Ideally we should be able to generate them with boost build but a manual doxygen call is fine. thanks, Daniel