mod_http_admin_api: Export total storage use via mod_http_file_share Does not include size of other user data, chat logs etc. Uploads will likely be a significant fraction of total storage use.

This module blocks configured queries that change server state.

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

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