mod_rest: Fill in 'type' field in error registry The 'type' defaults to "modify" in util.error, which doesn't quite fit many of these error conditions. LuaFormatter changed ',' to ';'

This module blocks configured queries that change server state.

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

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