Plugin: copy as cURL button

[judepereira]

I'm well aware that this is feasible via the dev tools for Chrome/Safari, however, that also copies all the cookies for my domain.

Additionally, Safari, for example, does not allow one to exclude cookies :(

[benjie]

I don't think we want this in core as most users won't need it, but I think it would be a good candidate for a plugin in our new plugin system.