DOC GH3508 (bis) added basic documentation of google analytics  in remot...
added the GA doc to the correct file: "remote_data.rst"
closes #3508

actually if you would add a release note (in Enhancements) in v0.15.2, with a pointer to the docs (e.g. see here)....then people will know about the new docs.

thanks
 Added entry in whatsnew for v15.0.2.
 For the rest, looks good to me! 
Can you squash both commits into one?
 merged via https://github.com/pydata/pandas/commit/9dd675b7a7f664f0d7773180c77d6f722d0647a5

thanks!
 @benoitpointet can you run this PR

https://github.com/pydata/pandas/pull/8785

and see if it removes the warnings that were previously generated. 

lmk
 Tested, it does indeed. It however does not remove the index_col bug described in #8773.
 k thanks...

#8773 is not a bug, or did this use to work? (e.g. has the format changed)? The user needs to specify the `index_col`?
 it used to work without​ having to provide the index_col argument.
b.
 if you want to somehow infer that the index_col is 0 that would be great!

(e.g if `index_col=None` is the default), then just try it, if it fails, then you can try with `index_col=0`). IF its unambiguous.

Ideally would have tests for this.....
 I'm unsure about hacking the `read_ga` function to infer such things.

If you look at the behaviour of the `index_col` param of the `read_csv` function for example, it support values such as `index_col=['start', 'end']` or `index_col=1`. That for me should be the default behaviour of the index_col param in read_ga. I'm still having a hard time figuring out why it does not behave so ...
