message: clean up push_transactions and performance enhancements
diff: @@ -269,13 +269,16 @@ read_write::push_transaction_results read_write::push_transaction(const read_wri
  return read_write::push_transaction_results{ pretty_input.id(), pretty_trx };
  }
  -read_write::push_transactions_results read_write::push_transactions(const vector<read_write::push_transaction_params>& params) {
  +read_write::push_transactions_results read_write::push_transactions(const read_write::push_transactions_params& params) {
  + FC_ASSERT( params.size() <= 1000, "Attempt to push too many transactions at once" );
  +
  push_transactions_results result;
  + result.reserve(params.size());
  for( const auto& item : params ) {
  try {
  - result.push_back( push_transaction( item ) );
  + result.emplace_back( push_transaction( item ) );
  } catch ( const fc::exception& e ) {
  - result.push_back( read_write::push_transaction_results{ chain::transaction_id_type(),
  + result.emplace_back( read_write::push_transaction_results{ chain::transaction_id_type(),
  fc::mutable_variant_object( "error", e.to_detail_string() ) } );
  }
  }
  