D-BUS Configuration API v0.1
----------------------------

The X server will register the bus name org.x.config.displayN, and the 
object /org/x/config/N, where N is the display number.

Currently only hotplugging of input devices is supported.

org.x.config.input:
    org.x.config.input.add:
        Takes an argument of key/value option pairs in arrays, e.g.:
         [ss][ss][ss][ss]
        is the signature for four options.  These options will be passed
        to the input driver as with any others.
        Option names beginning with _ are not allowed; they are reserved
        for internal use.

        Returns one int32, which is an X Status, as defined in X.h.  If
        everything is successful, Success will be returned.  BadMatch will
        be returned if the options given do not match any device.  BadValue
        is returned for a malformed message.

        Notably, BadAlloc is never returned: the server internally signals
        to D-BUS that the attempt failed for lack of memory.

        The return does not notify the client of which devices were created
        or modified as a result of this request: clients are encouraged to
        listen for the XInput DevicePresenceNotify event to monitor changes
        in the device list.

    org.x.config.input.remove:
        Takes one int32 argument, which is the device ID to remove, i.e.:
         i
        is the signature.
        Same return values as org.x.config.input.add.