Currently calling a mgr accessor during a plugins __init__ method causes
a cyclic locking exception.
Signed-off-by: Jan Fajerski <jfajerski@suse.com>
will be very rare transient states, but plugins should be written
to cope with the possibility.
+Note that these accessors must not be called in the modules ``__init__``
+function. This will result in a circular locking exception.
+
``get(self, data_name)``
Fetch named cluster-wide objects such as the OSDMap. Valid things