Create a new handle to an Sdb account. All handles share the same per process or per thread HTTP connection to Amazon Sdb. Each handle is for a specific account. The params are passed through as-is to Aws::SdbInterface.new Params:

   { :server       => 'sdb.amazonaws.com'  # Amazon service host: 'sdb.amazonaws.com'(default)
     :port         => 443                  # Amazon service port: 80 or 443(default)
     :protocol     => 'https'              # Amazon service protocol: 'http' or 'https'(default)
     :signature_version => '2'             # The signature version : '0', '1' or '2' (default)
     DEPRECATED :multi_thread => true|false           # Multi-threaded (connection per each thread): true or false(default)
     :connection_mode  => :default         # options are :default (will use best known option, may change in the future)
                                                 :per_request (opens and closes a connection on every request to SDB)
                                                 :single (same as old multi_thread=>false)
                                                 :per_thread (same as old multi_thread=>true)
                                                 :pool (uses a connection pool with a maximum number of connections - NOT IMPLEMENTED YET)
     :logger       => Logger Object        # Logger instance: logs to STDOUT if omitted
     :nil_representation => 'mynil'}       # interpret Ruby nil as this string value; i.e. use this string in SDB to represent Ruby nils (default is the string 'nil')
     :service_endpoint    => '/'              # Set this to /mdb/request.mgwsi for usage with M/DB