Downloading all Map Server

[latot]

Hi hi, related to https://github.com/openaddresses/pyesridump/issues/61

Downloading an entire layer is great, get all of the layers is more great, and get all the server is more!

I think would be great add te next thing, and is download with info of every service/map/layer.

About the format, we would think "lets download all in json", but I found something curious, ex, if you download the html version, it will have different info if we compare to the json version, maybe, for the info, download in all available formats and compress them in one file.

Other weird thing, the available features, like identify/query/etc, some times, the map says, "is available", but you can't do almost anything with it.

Here a very brute implementation: https://github.com/latot/pyMapEsriDump

Thx.