Provide more detail in exceptions resulting from curl errors

[rbone]

This pull request adds the curl error number and timing information to exceptions resulting from curl errors.

[richo]

Worth trying to log the URL and params as well (does this expose an info leak in commerce?)

Right now it's pretty possible to infer it from the stack trace, but in many cases it'd be handy to track down an error, I suspect.

[richo]

EDIT: Definitely useful in the case of loadbalanced connections, ie elasticsearch.

[rbone]

@richo Sounds good to me. I've added the url to the exception message including the query string.

[richo]

Nice one. :ship: it.