Copy the virtlockd codebase across to form the initial virlogd
code. Simple search & replace of s/lock/log/ and gut the remote
protocol & dispatcher. This gives us a daemon that starts up
and listens for connections, but does nothing with them.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

A earlier commit changed the global log buffer so that it only
records messages that are explicitly requested via the log
filters setting. This removes the performance burden, and
improves the signal/noise ratio for messages in the global
buffer. At the same time though, it is somewhat pointless, since
all the recorded log messages are already going to be sent to an
explicit log output like syslog, stderr or the journal. The
global log buffer is thus just duplicating this data on stderr
upon crash.

The log_buffer_size config parameter is left in the augeas
lens to prevent breakage for users on upgrade. It is however
completely ignored hereafter.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Each new VM requires a new connection from libvirtd to virtlockd.
The default max clients limit in virtlockd of 20 is thus woefully
insufficient. virtlockd sockets are only accessible to matching
users, so there is no security need for such a tight limit. Make
it configurable and default to 1024.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

The virtlockd daemon will maintain locks on behalf of libvirtd.
There are two reasons for it to be separate

 - Avoid risk of other libvirtd threads accidentally
   releasing fcntl() locks by opening + closing a file
   that is locked
 - Ensure locks can be preserved across libvirtd restarts.
   virtlockd will need to be able to re-exec itself while
   maintaining locks. This is simpler to achieve if its
   sole job is maintaining locks
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>