Execution now carries both into and out of a driver. Successfully call into
udi_usage_ind for new device instances, and successfully intercept udi_usage_res
calls out of them.

* New ZUI header.
* Namespace zudiIndexServer:: renamed to zuiServer::.
* New unique_ptr clone types. Now we no longer need an extra variable to track
  whether or not memory was array allocated.
* New macro: FVFS_PATH_MAXLEN: defines the max length for an FVFS path.
  ^ Propagated through the kernel.
  ^ Replaces the disjoint uses of ZUDIINDEX_SERVER_MSG_DEVICEPATH_MAXLEN.