Export a function for parsing conninfo strings

[johto]

I was about to copy-paste our code for an app I'm working on, but I thought I'd do one better and make this available for everyone. Example usage:

opts := make(pq.ConninfoOptions)
err = pq.ParseConninfo("host=foo bar=baz", opts)
if err != nil {
    panic(err)
}
fmt.Printf("%+#v\n", opts)

Thoughts?

[jenanwise]

I'd love this. I'm currently duplicating parsing logic in my custom driver wrapper around pq.

[ajvb]

+1