ReadOnlyDirectories=... for whitelisting files for a service.
* sd-bus:
- - bus-proxy: fix how we detect whether we are connected to a system bus
+ - xml policy inforcement and bus activated services is broken?
+ - rework errno registration logic
+ - how can we make the xml enforcement for native clients unnecessary?
- kdbus: the kernel should not allow messages to be delivered that have a reply serial != 0, reply-expect unset, but no appropriate window
- kdbus: when we fake creds euid being (uint32_t) -1 is weirdly translated
- kdbus: timestamps on kernel's NameOwnerChanged messages?