added shared memory config parameter, signum for use in signalling
added global variable for holdign signum to be used for shared memory connection
only fiddle with signals if it is set
simplified common ndb client option handling
moved NdbWaiter, m_ndb_cluster_connection, to impl class
moved node selection things to cluster connection
moved all private things to impl class
added opts for shared memory and node selection
changed opts handling somewhat; introduced enum for options and common handling of option variables
added checks for transporter support
automatic addition of shared mem transporters
moved wait_until_ready code to cluster connection
added control of usage of new node selection method
