Less pinging & Model -> create_many() .

Example:

Author -> create_many( [ name => 'Paul',
			 age => 99 ],

		       [ name => 'John',
			 age => 18 ],

		       _debug => 1 # if needed
                     );

Model -> create() optimized, no more extra get() call to build return value.
even less pingin
Get back that ping() for now.
WIP on having 2 separate sets of database handles for reading and writing
WIP, possibly broken (although tests ok)

New ORM::Db init for multiple $dbh handles (for read/write distributing):

ORM::Db -> init( { read => [ $dbh1, $dbh2, $dbh3 ... ],
		   write => [ $dbh4, $dbh5 ... ] } );

Model::Class -> set_dbh( { read => [ $dbh1, $dbh2, $dbh3 ... ],
			   write => [ $dbh4, $dbh5 ... ] } );

Less usable:

Model::Class -> set_read_dbh( [ $dbh1, $dbh2, $dbh3 ... ] );

Model::Class -> set_write_dbh( [ $dbh4, $dbh5 ... ] );
more work on $dbh for read/write separation
More correct handling of  _dbh => $dbh when passed.