communicate with device-mapper directly. Our lvm stack now looks like this
lvm<->libdevmapper<->libdm<->dm where only libdm knows how our dm protocol
looks like.
No objections on tech-userlevel@.
- Centralize CPPFLAGS for DM_DEVICE_{UID,GID,MODE}
- Make DM_DEVICE_GID operator DM_DEVICE_MODE 0640 to be more NetBSD like
- make all the code use DM_DEVICE_MODE instead of hard-coding.
- make sure that all mknod calls are followed by a chown call.
