mod_http_oauth2: Refactor scope handling into smaller functions Goal is to put a dropdown on the consent page with your allowed roles. Smaller functions make it easier to reuse. Readability may be improved slightly as well.

This module blocks configured queries that change server state.

E.g. to make vCard storage read-only:

``` lua
readonly_stores = {
	vcard = { "vcard-temp", "vCard" };
}
```