add optional usage of hugsql options in bind-connection

[nottmey]

PR for #25

In bind-connection I needed to reuse part of the variadic parameter filenames to not break backwards compatibility. This feels a bit awkward because the possibility for options is hidden in the code, but we can go with it for simplicity.

Another solution would be to offer another differently named function for advanced "bind-connection" use. The signature may look like this:

(defn bind-connection-opts [conn options & filenames] ...)

Since this opens up more design space, I tried to anticipate other advanced behaviors:

• It is not possible to explicitly define the namespace for generation (besides wrapping bind-connection in (binding [*ns* 'some.namespace] ...)
• It is not possible to programmatically generate the filenames (e.g. (bind-connection *db* (file-seq (io/file (io/resource "seeding"))))), without wrapping bind-connection in clojure.core/apply.

So an advanced "bind-connection" function might also look like:

(defn bind-connection-with [conn namespace options filenames] ...)
; Usage:
(bind-connection-with *db* 'myapp.db {:quoting :mysql} (collect-sql-files))

Any preferences?

After we settled for a solution I can also add a test case for it.

[yogthos]

I think I'm ok with current approach of passing an optional config map. The connection and the namespace could be passed as part of the options map. As long as that's documented, I don't think it should be a problem. However, using a separate bind-connection-with macro might be a good idea to keep it explicit. I'd be ok with either approach.