mod_http_oauth2: Allow omitting application type for native apps This derives "application_type":"native" from the first redirect URI when registering a client, so that it can be omitted without the default value of "web" causing the very same redirect URIs to be rejected.

This module blocks configured queries that change server state.

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

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